colossal camera pushes the limits of fabrication
Transcription
colossal camera pushes the limits of fabrication
March 2007 Issue 148 The European magazine for photonics professionals LENS DESIGN B AC K C H AT FIBRE LASERS Thin lens looks for applications in mobile phones Kaleido Technology CEO reveals secrets to start-up success Bismuth-doped fibres offer route to pulsed all-fibre laser sources L ARG E O P TI C S COLOSSAL CAMERA PUSHES THE LIMITS OF FABRICATION optics.org Project6 26/1/07 13:17 Page 1 EDITORIAL Editor Jacqueline Hewett Tel +44 (0)117 930 1194 jacqueline.hewett@iop.org News editor James Tyrrell Tel +44 (0)117 930 1256 james.tyrrell@iop.org Production editor Alison Gardiner Technical illustrator Alison Tovey I s s u e 14 8 M a r c h 2 0 07 NEWS 5 Business EUROPE/ROW SALES Business development manager Adrian Chance Tel +44 (0)117 930 1193 adrian.chance@iop.org Halma buys Labsphere for $14 m•French government gives 75.6 m to Imalogic project•People 10 Group advertisement manager Rob Fisher Tel +44 (0)117 930 1260 robert.fisher@iop.org Advertisement manager Cadi Jones Tel +44 (0) 117 930 1090 cadi.jones@iop.org Senior sales executive Katrina Davis Tel +44 (0) 117 930 1284 katrina.davis@iop.org French government funds digital sensor project p6 US SALES IOP Publishing Inc, Suite 929, 150 South Independence Mall West, Philadelphia PA 19106, USA Tel +1 215 627 0880. Fax +1 215 627 0879 CHINA SALES China sales executive Ann Hou Shenzhen Yongge Advertising Co Ltd, Rm 1106, Xinwen Building, No. 2 Shennan Zhong Road, Shenzhen, Guangdong, PRC Tel +86 755 82091822. Fax +86 755 82090566 ann@indus-sources.com It’s all about fibre mPOF includes internal biosensor•Holes improve microsphere imaging•IR sensor studies ant activity 15 R&D 16 Patents Snow improves coupling efficiency•Bismuth boosts all-fibre lasers LED giants Osram and Philips agree to cross-licence patents•Fibre firms announce “amicable” settlement of dispute F E AT U R E S 17 Laser water jet cuts it in the material world After 10 years in the making, Synova’s water-jet-guided technology is being used to cut, drill, grind and dice materials as varied as gallium arsenide and polycrystalline diamond. Jacqueline Hewett catches up with Synova to find out the advantages of the approach. IR sensor counts ant activity around nest site p14 Advertising production editor Mark Trimnell 20 CIRCULATION AND MARKETING Subscription and circulation manager Jenny Brown Tel +44 (0)117 930 1034 jenny.brown@iop.org UK produces giant camera for IR astronomy An infrared, 67 Mpixel, 3 tonne camera has been successfully installed on the VISTA telescope in Chile. Martin Caldwell from the UK’s Rutherford Appleton Laboratory explains how the instrument pushed the limits of large-scale optics. ART DIRECTOR Andrew Giaquinto Laser water jet cuts groovy patterns in OLED masks p17 23 Nerve stimulation gets IR light treatment Stimulating nerves with pulses of infrared light could help to restore a person’s balance, intensify hearing implants and lead to more advanced prosthetic limbs. James Tyrrell talks with Mark Bendett to discover more about Aculight’s role in this up-andcoming research area. OPTICS & LASER EUROPE Dirac House, Temple Back, Bristol BS1 6BE, UK Tel +44 (0)117 929 7481 Editorial fax +44 (0)117 925 1942 Advertising fax +44 (0)117 930 1178 optics.org/ole ISSN 0966-9809 CODEN OL EEEV SUBSCRIPTIONS Complimentary copies are sent to qualifying individuals. For readers outside registration requirements: £116/7168 ($208 US and Canada) per year. Single issue £11/715 ($19 US, Canada and Mexico). Contact IOPP Magazines, WDIS Ltd, Units 12 & 13, Cranleigh Gardens Industrial Estate, Southall, Middlesex UB1 2DB, UK. Tel +44 (0)20 8606 7518. Fax +44 (0)20 8606 7303 Editorial T E C H N O LO GY 11 Applications ADVERTISING PRODUCTION Advertising production coordinator Rachel Sermon Tel +44 (0)117 930 1277 rachel.sermon@iop.org PUBLISHER Claire Bedrock Tel +44 (0)117 930 1151 claire.bedrock@iop.org Contents 25 Capella laser optically stimulates nerves p23 Imaging colorimeters give advanced options CCD-based instruments can provide accurate measurements of spatial colour and luminance information for displays, instrument panels, light sources and luminaires. Sean Skelley, Doug Kreysar and Kevin Chittim weigh up the options when buying imaging colorimeters. PRO D U C T S 29 Power and energy meters•CCD cameras•Integrating sphere © 2007 IOP Publishing Ltd. The contents of OLE do not represent the views or policies of the Institute of Physics, its council or its officers unless so identified. Printed by Warners (Midlands) plc, The Maltings, West Street, Bourne, Lincolnshire PE10 9PH, UK. REGULARS 38 Back chat Cover (VISTA project) Giant IR camera united with VISTA telescope p20 For the latest news on optics and photonics don’t forget to visit optics.org Project1 5/2/07 13:28 Page 1 1 Create Control Position Blue Solid-State Laser • 488-nm output • Excellent pointing stability The Practical Application of Light Laser Solutions for Fluorescence • Efficient and compact 325 375 408 440 442 454 457 465 472 473 476 483 488 496 502 Melles Griot lasers are available with over Yellow DPSS Laser • 561-nm output • Excellent beam quality, low noise • Common controller with 488-nm laser 38 wavelengths, suitable for exciting your 514 520 532 543 561 entire range of fluorophores. Ask about 568 594 612 our line of solid-state solutions for the ultimate in stability, reliability, compact 633 635 638 647 670 675 size, and ease of operation. 676 685 752 780 830 840 1064 1523 High-Power Diode Lasers • 375- 408-, 440-, and 638-nm diode • Up to 50 mW • High-speed modulation shop.mellesgriot.com Find out more: 1-800-645-2737 or lasers.mellesgriot.com LASER GROUP Carlsbad, California | (760) 438-2131 | FAX (760) 438-5208 | sales@carlsbad.mellesgriot.com Asia +81 (03) 3407-3614 | Europe +31 (0316) 333041 N E WS B U S I N E S S 5 E D I T O R I A L 10 AC Q U I S I T I O N S Halma Labsphere, a US developer of light-measurement systems, has been acquired by Halma, a safety, health and sensor technology group based in the UK, for about $14 m (711 m) in cash. The purchase follows Halma’s acquisition of US spectrometer specialist Ocean Optics in June 2004, as the group continues to enhance its presence in the photonics market. Halma is a holding company of almost 50 subsidiaries worldwide, with reported revenues in 2006 of more than £300 m (7450 m). Labsphere fits into Halma’s health and analysis portfolio, which generated 38% (£23 m) of the group’s profit last year and is reportedly Halma’s fastest-growing business sector. “Labsphere has f irst-rate knowledge in laser and LED metrology applications,” Keith Roy of Halma told OLE. “It is a financially solid business with excellent growth potential.” Unaudited accounts for 2006 show that Labsphere delivered revenues of $12.5 m with an operating profit of $2.4 m. Halma Halma buys Labsphere for $14 m Easy to use: Labsphere offers a wide range of light-measurement solutions including out of the box systems for characterizing LEDs. Labsphere’s products include LED, laser and traditional lightsource light-measurement systems; uniform light sources for calibration; and high diffusereflectance materials and coatings for backlit displays. What’s more, the evolution of the fi rm’s technologies has resulted in multiple patents in LED testing and ultraviolet transmittance. “One of the exciting areas is the applicability of Labsphere’s unique intellectual property to other Halma com panies, providing immediate potential for Keith Roy: Halma remains very interested in the photonics sector. its headquarters in North Sutton, New Hampshire. “Both companies will continue to be branded and promoted independently,” added Roy. “That said, we will look for marketing collaborations, such as combining physical presences at trade shows, where appropriate.” According to Roy, Halma remains very interested in making further acquisitions in the photonics sector – specifically in areas where the enabling technology resides in a number of different markets. product-performance enhancement,” said Roy. “Innovation is a corporate strategic goal of the group and Labsphere will be encouraged to support this.” Halma is a keen investor in R&D, spending almost 5% of its health and analysis sector revenue on R&D activity within the division and launching more than 60 new products. Labsphere is likely to benefit from Ocean Optics’ global distribution network as a way of providing new routes to customers. It will continue to operate from O P T I C A L N E T WO R K S Giorgio Anania has stepped down as Bookham’s president and CEO after eight years of service. Peter Bordui, a former director of New Focus, which was acquired by Bookham in 2004, and current non-executive chairman of the board, will assume the CEO role on an interim basis. Anania played a key role in Bookham’s highly successful initial public offering in April 2000, which helped to transform the company from its beginnings as a niche supplier of silicon photonics. Today, through its acquisition policy, the company designs, manufactures and markets optiO L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e cal components, modules and subsystems for a broad range of markets, including telecommunications, aerospace, semiconductor and defence. According to Bookham, the resignation was reached by mutual agreement between Anania and the company’s board of directors. “We thank Giorgio for his hard work and dedication to Bookham over the past eight years,” said Bordui. The news comes just two weeks after the company announced a $21.3 m (716.1 m) loss for the second quarter of 2007 and disclosed that it was undertaking an “aggressive overhead cost- reduction plan” designed to save around $6–7 m this year. The firm said that the savings will come mainly from reductions in its workforce, consolidation at its UK semiconductor operation in Caswell, and shifting more development activities to China. On a more positive note, as OLE went to press, the company revealed that its 980 nm pumplaser technology has been selected by US firm Tyco Telecommunications for deployment in undersea cable systems. Dubbed OceanBright, the products will be used in erbium-doped fibre amplifiers, which perform a critical repeater function in optical networks. Bookham Anania resigns as CEO of Bookham Resigned: after eight years of service with Bookham, Giorgio Anania has stepped down as president and CEO. The deal is a significant endorsement of Bookham’s technology as Tyco is one of the key players in this market. Tyco hopes to achieve production cost savings by applying the 980 nm pump technology to terrestrial and submarine systems. 5 NEWS BUSINE S S L A S E R T E C H N O L O GY The Florida Photonics Center of Excellence at the University of Central Florida (UCF), US, has been awarded $4.5 m (73.4 m) to establish a new programme on advanced laser technologies. The Laser Technology Initiative, one of six programmes recently approved across Florida, will focus on nanophotonics, biophotonics, optical imaging and communications. To further enhance the initiative, UCF provost Terry Hickey and other state programmes are providing an extra $9.6 m to enable the hiring of staff and to build the infrastructure. I N T E G R AT E D O P T I C S Infinera, Sunnyvale, US, has acquired Little Optics, a developer of planar lightwave circuits. Based in Annapolis Junction, Maryland, US, Little Optics has pioneered the development of integrated optical devices using a combination of planar-lightwave technology and proprietary glass materials. TELECOMS Following the announcement of 12 500 job cuts worldwide, to take place over the next three years, Alcatel-Lucent (A-L) has been meeting representatives of the Dutch Works Council and unions to discuss how the company’s plans will affect employees in the Netherlands. “Up to 180 staff will be going over the next 24 months,” said Coert de Boer, managing director for the Netherlands. Currently, A-L employs some 700 people in the country. OPTICAL SENSING French government gives 95.6 m to Imalogic project Sofradir, a developer and manufacturer of infrared detectors, has revealed a major step forward in the 723 m digital-sensing initiative – Imalogic. According to the fi rm, the French government is set to contribute 75.6 m to the project that involves Sofradir, Ulis, Trixell and STMicroelectronics. Imalogic brings together the research and development resources of four of the world’s leading digital-sensor manufacturers, as well as incorporating the microelectronics know-how of CEA-LETI. The partners will collaborate to develop a range of digital sensors for various professional and commercial applications. Sofradir will focus on high-definition infrared detectors for aerospace and security markets. Ulis is primarily targeting the automobile industry. Trixell and STMicroelectronics will work together to tap into the medical X-ray sector. The financial support is part of a French Finance Ministry initiative to help French industry become more competitive globally. Sofradir, Ulis, Trixell and STMicroelectronics will invest about 70% in Imalogic. The French Finance Ministry, as well as regional agencies and municipalities in and around Grenoble, where the companies’ research and development centres are based, will contribute 30%. “Grenoble has a long tradition Sofradir IN BRIEF Philippe Tribolet: Sofradir is taking a lead role in managing the Imalogic project. of successful alliances linking research, education and industry,” said project leader Philippe Tribolet, vice-president of research and development, technologies and products at Sofradir. “The partners and I are thrilled about the state supporting industry and research-led innovation here. This contribution is a major step towards helping us achieve our mutual objectives.” Imalogic is one of 30 microand nanotechnology, and embedded system-on-chip projects that Minalogic, a global competitive centre for microsmart devices, is supporting. Sofradir is taking a leading role in managing the project that is scheduled for completion in 2009. A detailed investigation of the constraints that exist in the base technologies, which are common to all and impact on product performance, is already under way. The next step is to optimize the synergies found in the methodologies, design tools and equipment used by the partners. CEA-LETI’s role will be to help the fi rms by developing base technologies and new component architectures that lower production costs. Imalogic members hope to win greater market share in the commercial sector over the next 5–10 years. The firm expects to increase revenue and create new jobs as a direct result of the project and the competitiveness of the digital sensor products that will be produced. “Each member will greatly benefit from the shared knowledge and skills that are being pooled in semiconductor materials and information processing, as well as in integration and encapsulation technologies,” continued Tribolet. “We believe that Imalogic will enable us to overcome some well known technological barriers and open up new market opportunities in the whole spectral band from X-ray to infrared.” new monitors SOLO 2 UNO w w w. g e n t e c - e o . c o m 6 O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e The speed of light just got faster. To match the speed of your imagination. Bring your designs to life with DMD Discovery products from Texas Instruments. DMD DiscoveryTM Products contain the same light modulation technology used in DLP® Projectors and TVs. These semiconductor-based “light switches” have arrays of thousands of individually addressable, tiltable, mirror-pixels. The DMD is the only volume production device that is both a micro-electronic mechanical system (MEMS) and a spatial light modulator. This brings many advantages to light-steering applications. With more than ten million systems shipped since 1996, the DMD has proven its resilience and dependability. The only limit to their potential Features • Switching speed of more than 5,000 times/sec • 85% optical fill factor • Up to 16,300 full array mirror patterns/sec (12.8 Gbs) is your imagination. Light hits the mirrors, the mirrors in the “on” position reflect the light; the mirrors in the “off” position steer the light away. For more information on the DMD Discovery Developer Kit, visit www.dmddiscovery.com The red/black bar is a trademark of Texas Instruments. DLP, the DLP logo and DMD Discovery are registered trademarks of Texas Instruments. Texas Instruments is traded publicly on the NYSE® under the symbol TXN. 1229A1 © 2007 TI. Applications • Biotech • Lithography • Medical imaging • 3D Metrology • Photofinishing • Scientific instrumentation • Spectroscopy • Telecom applications • Volumetric display • Your world-changing idea NEWS BUSINE S S PE O PLE O P T I C A L SY S T E M S Gerd Litfin and Nils Stoesser have taken up roles on the supervisory board of LINOS AG as of 1 January. Litfin and Stoesser succeed Reinhold Barlian and Gottfried Neuhaus, while Gerd Kastrup retains his position. Litfin is the founder of the LINOS Group and was chief executive officer of LINOS AG until the end of December 2006. Stoesser is the director of Candover Partners Limited, a private equity firm. M E T R O L O GY Zygo has appointed James Northup as president of its metrology division. Northup joined the company as executive vice-president of corporate business development. Prior to joining Zygo, Northup was chief operating officer at Toppan Photomasks (formerly DuPont Photomasks Inc) and president of Photronics Inc. He holds a BSc, with distinction, in chemical engineering from the University of Rhode Island. advanced systems analysis program in 35 countries. Matty has 13 years of sales and customer service experience in high technology. OLEDS Harry Boehme has joined OLEDdeveloper Novaled of Germany as chief financial officer and member of the management board. “The arrival of Harry on our management board occurs at the proper time for further developments at Novaled,” said Novaled’s chief executive officer Gildas Sorin. S C I E N C E P O L I CY Thomas Giallorenzi has joined the OSA as senior director of science policy. Giallorenzi will help to expand the society’s programmes and activities, with particular emphasis on widening its conventions and meetings portfolio. S O F T WA R E Breault Research Organization (BRO) has promoted Kimberly Matty to the position of vicepresident of global sales. In her new role, Matty will lead BRO’s team of sales representatives and engineers supporting the company’s LASERS Synova, the pioneer of water jetguide laser technology, has named Notker Kling as general manager of its North American operations. Kling will oversee operations at Synova’s two US micromachining centres in Boston and Silicon Valley, and help to build adoption of the company’s Laser MicroJet technology. OPTICS Melles Griot has promoted Sherie Motakef to the position of marketing manager for the company’s distribution group. This position carries responsibility for all aspects of catalogue and web marketing to Melles’ North American and European client base. Motakef will be based in Carlsbad, California, US, and will report to general manager Jacky Byatt. COMPONENTS Pacer International has employed David House to head its new US sales and support team. The company recently opened a new office in Blue Bell, Philadelphia, which will be the headquarters of its North America operation. House joins Pacer from Perkin Elmer where he was western US sales leader for the optoelectronic industrial sensors division. optics New Optics, More Optics Unaxis Optics, the global leader in high-volume custom optical components and solutions, is now Oerlikon Optics. The new, strong Oerlikon brand name embodies our Swiss heritage and long tradition of excellence. Oerlikon Optics possesses comprehensive know-how in optical thin films, glass processing, lithography and the production of optical subassemblies. The synergies with other Oerlikon business units offering state-of-the-art vacuum technology combined with our know-how give us a clear competitive edge. www.oerlikon.com/optics Europe/Headquarters Balzers/Liechtenstein sales.optics@oerlikon.com T +423 388 4444 8 USA Golden/Colorado sales.optics.go@oerlikon.com T +1 303 273 9700 Asia Shanghai/China sales.optics.sh@oerlikon.com T +86 21 5057 4646 O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e OLEJMarAdPage9 28/2/07 11:23 Page 1 If it’s not Newport, it’s not Oriel! Newport is the only source for Oriel products in Europe. Know who you are buying from get the best prices, best service and fastest delivery… directly from the manufacturer. Save time and money – buy your Oriel products direct from Newport. Newport offers the broadest selection of Oriel light sources and spectroscopic instruments, such as UV-IR CW sources, solar simulator, monochromators, spectrographs, and dispersive and FT-IR spectrometers. Special Discount Offer! Get 15% Off Oriel Solar Simulators between 1/4/07 and 28/9/07 For more information, contact your local Newport sales office. See Newport's complete Oriel products offering at www.newport.com/oriel One place, one source for all your Oriel needs – Only at Newport! Belgium Tel: +32-(0)16 40 29 27 France Tel: +33 (0)1.60.91.68.68 Germany Tel: +49 (0) 61 51 / 708 – 0 Italy Tel: +39-(0)2/92.90.921 Netherlands Tel: +31-(0)30 659 21 11 United Kingdom Tel: +44 (0)1235 432710 MAKE LIGHT | MANAGE LIGHT | MEASURE LIGHT AD-020708-EN PRODUCTS PROCESSES Looking for Polymer Optics ? Realize your product ideas by making full use of our comprehensive know-how and experience. Development New Products • Polymer Optics • Fujistraße 1 • D-47533 Kleve/Germany Tel. +49-2821-509-0 • Fax +49-2821-509-184 E-mail: polymer-optics@eu.fujifilm-rme.com • www.polymer-optics.com • • • • • • • • • • Optical Design Mold Manufacturing Ultra Precision Machining Injection Molding Clean Room Production Coating Technology Precision Metrology Quality Control Automation Assembling and Packaging • • • • • • • • • • Precision Lenses Ophthalmic Glasses Optical Freeform Hybrid Surfaces Polymer Optical Systems Micro-Lenses and Arrays Precision Mirrors Optical Gratings Micro-Fluidics Prototyping NEWS EDITORIAL LASER 2007 It’s all about fibre World of Photonics E-mail Alerts “ Synova is confident that its water-jet products can replace existing methods.” Jacqueline Hewett Sign up for the free optics.org e-mail alert now to receive independent and exclusive news from LASER 2007. This series of focused alerts will contain exhibitor profiles, conference hot topics and product launches. optics.org/signup Laser NewsAlert sponsors It’s hard to believe that here we are putting the final touches to the March issue of OLE. Photonics West took place more than a month ago and it still feels as though we are digesting all of the technical innovation that was on show both in the exhibition and during the conferences. Fibre lasers are always a popular topic and this was certainly the case at Photonics West. One company raising its voice and looking to increase its share in the micromachining market was Synova. This Swiss firm is the pioneer of water-jet-guided laser technology and confidently believes that this approach can be adopted wherever a normal laser is being used. This is all thanks to the eyecatching list of advantages of using a waterjet rather than focusing a laser beam directly onto a workpiece. Turn to p17 to read more about the technology. In this issue you will find news of a fibre-coupled laser being used to optically stimulate nerves (p23). The source and its applications are being developed by Aculight and several US universities. Aculight believes that its Capella product, although currently just an investigative tool, will be adopted in curative applications and is keen to work with other research groups. “We would like to disseminate the technology across as many clinical platforms as possible,” Mark Bendett, Aculight’s director of product development, told OLE. “And the easiest way for us to do that is to put it out to dozens of research groups that can then work with us on the technology.” To marvel at how far optical technology can be stretched, turn to p20 to read about a giant 67 Mpixel, 3 tonne camera that was installed on the VISTA telescope in Chile in February. Described as a real colossus among optical cameras, it just managed to fit within the largest cargo container allowed on a Boeing747. The camera pushed large-scale optics to the limits: a 1.4 m diameter filter wheel and lenses that are 0.6 m in diameter are two of many examples. And when you factor in the earthquake-prone environment of Chile, that presents a whole new problem when it comes to getting things aligned. Enjoy the issue. Jacqueline Hewett, editor E-mail jacqueline.hewett@iop.org 10 O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e TEC HNOLOGY A PPLI CAT I O N S 11 R& D 15 PAT E N T S 16 SENSING mPOF includes internal biosensor “We have drawn around 250 m of Topas mPOF in around 30 min,” he said. “The mPOF has 3 holes running along its length, each around 50 µm in diameter.” To turn the fibre into a biosensor, Emiliyanov and colleagues exploit the fact that Topas is chemically inert and that direct binding of biomolecules onto its surface is difficult. “Com mercia l ly ava i lable Antraquinion (AQ) linker molecules can attach to the Topas surface when activated with ultraviolet [UV] light and can then accept sensor layers,” explained the researchers. “As a consequence, a UV mask can be used to define localized sensor layers inside a Topas mPOF.” The team fi lled a 30 cm-long Topas mPOF with a solution containing AQ molecules. After a 1 h incubation period, half of the Grigoriy Emiliyanov Danish researchers have created an unusual fibre-optic biosensor by exploiting the properties of microstructured polymer optical fibre (mPOF) fabricated from a material called Topas. The team’s device contains localized sensing regions within the air holes that run along the length of the fibre (Optics Letters 32 460). “We believe that this is the fi rst mPOF to be fabricated from Topas cyclic olefi n copolymer,” said the researchers. Traditionally, mPOFs are fabricated from polymethyl methacrylate (PMMA) and their optical properties are dictated by the relative position, size and shape of the internal air holes. “Topas has attractive material properties (no monomers and very low moisture absorption – about 100 times lower than that of PMMA) and it is also chem- The researchers used a Topas mPOF with three holes running along its length to create their fibre-optic biosensor. ically inert,” explained the team. “It exhibits an improved melt viscosity and high tear strength, allowing better conditions for drawing optical fibres.” Researcher Grigoriy Emiliyanov, from Technical University Denmark, told OLE that the starting point is a preform 70 mm in length and 25 mm in diameter. fibre was illuminated with a UV lamp emitting at 325 nm, resulting in localized binding of AQ molecules, which in turn created localized sensing layers via an antigen–antibody binding detection procedure. Analysis using fluorescently labelled antibodies confi rmed that the sensing layer existed only where the fibre had been exposed to UV light. “We believe that defi ning the sensing layer locally in a section of the fibre introduces the possibility of up-concentrating the target mole cules in a confined region,” said Emiliyanov. “This is advantageous for grating-based sensor configurations for labelfree detection of biomolecules.” “The next step is to improve the fabrication process and be able to draw Topas mPOF with better guiding properties, such as singlemode,” concluded Emiliyanov. I M AG I N G By A L Narayan Engineers from the University of California at San Diego (UCSD), US, have developed a camera lens that they say is more than five times thinner than its conventional counterparts. The new design, which sees tiny mirrors embedded in a single optical crystal, derives its operation from Cassegrain telescopes and could lead to a new generation of slim lenses for mobile-phone cameras (Applied Optics 46 463). While today’s cameras focus light by using a set of compound refractive lenses placed next to each other, the new lens reflects light back and forth inside a thin optical crystal made of calcium fluoride. “All the power in this crystal is reflective, and there is only a small refractive compo- O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e nent that gets introduced when light enters the plane-annular aperture,” UCSD’s Eric Tremblay told OLE. The prototype plano-aspheric optic is 6 cm wide and 5 mm thick. Its front side is flat and has a reflective central core surrounded by a thin ring-shaped aperture. The rear face is aspheric and has a series of black and silver rings surrounding an aperture for connecting a CMOS sensor. Light entering from the annular aperture bounces along the two reflective surfaces while making its way to the sensor. “We call it the eightfold annular design, because two incoming light rays would encounter exactly eight mirrors on their way to the sensor,” explained Tremblay. Four concentric mirrored UCSD Folded optics enables ultrathin camera lens The “eightfold” lens is only 5 mm thick. the surfaces is aspheric, all of the reflective surfaces (in the rear portion of the lens) can be shaped in a single mounting,” said Tremblay. The team has built a basic digital camera with a resolution of 1024 × 768 pixels to demonstrate the power of its lens. Images taken with conventional camera lenses and the origami lens were compared and found to be very similar. However, the new design suffers from a smaller field of view (FOV) and depth than conventional cameras. While the FOV cannot be enhanced – which might preclude its use in high-end digital cameras – wavefront coding can be used to increase its depth. The current prototype has a fi xed focal length, but the team is now designing variable-focus crystals that have air between the two reflective surfaces. rings are located at precise positions on the disk to create a pathway for the light-rays. Light entering the annular aperture is forced to strike the largest of the concentric ref lectors and then follows a zigzag path to the smallest reflector before arriving at the CMOS sensor. Baff les made from a black light-absorbing material were fabricated between the mirrors to prevent stray light from interfering with the images. The mirrors were cut into the calcium fluoride slab using dia- A L Narayan is a freelance writer mond turning. “As only one of based in Singapore. 11 TECHNOLOGY APPLICATIONS MICRO - OPTICS Holes improve microsphere imaging of gold (40–120 nm) or nickel (60 nm). They then exposed the uncoated side of the sample to a Ti:sapphire source with a wavelength of 797 nm and a pulse duration of between 100 fs and 10 ps, to form an aperture in each microsphere. As Baeuerle explained, it is critical to match the laser pulse to the diameter and material properties of the metal-coated microspheres. These spherical lens-like particles can display strong aberrations and the addition of a welldefined, round aperture helps to diminish imaging faults by behaving as an iris. To understand the fabrication process better, the team modelled the intensity distribution Johannes Kepler Univer sity Linz Confocal microscopy and parallel laser-surface processing are two key areas that could benefit from a laser-fabrication process being developed at Johannes Kepler University Linz, Austria. Researchers used a Ti:sapphire source to generate well-defined, round apertures in a monolayer of either gold- or nickel-coated, amorphous quartz (SiO2) microspheres (Appl. Phys. Lett. 89 261104). “The apertures significantly improve the imaging properties of the microspheres,” Dieter Baeuerle, head of the Institute for Applied Physics, told OLE. “Femtosecond laser-induced forward transfer is the only technique that permits the fabrication of apertures on microlens Apertures in a monolayer of gold-coated, amorphous quartz microspheres created using a single pulse of Ti:sapphire laser radiation. arrays of this type.” First, the researchers deposited an aqueous solution of microspheres onto a quartz slide and coated the resulting monolayer structure with a fi lm of a plane-wave incident on a sphere and used the results to determine suitable operating parameters. Currently it can create well-defined apertures as small as 0.1 µm (radius) in a 75 nm thick gold fi lm, with a fluence of 40 mJ/cm 2 and a pulse duration of about 130 fs. Experiments with nickelcoated microspheres revealed that the metal offered increased protection against laser ablation of the quartz surface. The scientists believe that this is related to the higher absorptivity of the nickel film compared with gold. Bauerle was unwilling to comment on the next steps for his team but it appears to be focused on optimizing its process. Casting technique puts new spin on polymer antireflection coatings Spin-casting polymer latex onto glass is a convenient and reproducible way to fabricate antireflection (AR) coatings, say researchers at Sichuan University, China. As it is widely used in the electronic industry, the team believes that spin casting could be used in mass-production environments (Optics Letters 32 575). “Polymer latex is on the nanoscale and can be prepared easily, so we tried to assemble a nanoporous surface by spin-casting,” Yuechuan Wang from Sichuan’s College of Polymer Science and Engineering told OLE. “The present work is a promising start 12 and is applicable to flat optics.” Forming nanoporous structures on the surface of highly transmissive optical components is an attractive way to produce AR coatings. Although methods such as particle deposition have yielded excellent AR properties, the team says that these approaches are time-consuming compared with spin-casting. Wang says that it only takes a few minutes to coat an area of 100 cm 2. He adds that optical transmittances at 550 nm of 95.7% for a single-sided coating and 99.5% for a double-sided coating have been achieved. Yuechuan Wang, Sichuan Univer sity M AT E R I A L S SEM image of an antireflective coating made by spin-casting polymethyl methacrylate latex onto a glass slide. The refractive index and the thickness of the coating control the AR properties and both of these factors can be adjusted during spin-casting. “The porosity of the coating [which influences the refractive index] can be adjusted by changing the spin rate and the concen- tration of the coating solution,” he said. “The thickness of the monolayer particle film can be adjusted by using latex particles of the desired diameter and by forming multilayers.” Wang and colleagues Hao Jiang and Ke Yu prepared their polymer latex by the emulsion polymerization of methyl methacrylate. Filtered before use, the polymer latex was typically 110 nm in diameter. The team studied the resulting coatings using atomic-force microscopy and a scanning electron microscope (SEM). These methods revealed that the AR coatings were highly porous and highlighted the dependence on factors such as spin speed. O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e ElcanOpticslaserEurope(BkWrd):Layout 2 2/23/07 12:45 PM :elpoep fo sessalc eerht era erehT“ ees ohw esohT .ees ohw esoht .nwohs era yeht nehw ”.ees ton od ohw esoht dnA euqinu ynam ot yek eht sdloh NACLE gnirutcafunam ,stnetap lacitpo ortcele ,sessecorp hguorht-kaerb dna snoitavonni lacitpo fo tiusrup eht ni deniag lla .sseccus remotsuc dna noitavonni neeb sah NACLE sraey 061 ylraen roF ,secneics gnigami fo tnemecnavda eht gni dael s’yadot ot saremac mm53 tsri f yrev eht morf dna gninnacs lartceps-itlum ni smetsys tsetal elor ruO .yhp argoi dar latigi d scinortcele dna lacitpo etelpmoc ruoy eb ot si laitini gniretsam ,rentrap gnirutcafunam noitcudorp latot gnirewol dna segnellahc ngised dna ylkciuq evom stcudorp ruoy os stsoc .tekram ot ylevititepmoc You have a vision, let us show you the light. www.ELCAN.com Page 1 TECHNOLOGY APPLICATIONS L E D S/ D E T E C T O R S IR sensor sheds light on ant activity when ants enter or exit the nest during a given time. “Very-low-power and lownoise electronics were used for conditioning the signal and detecting changes in the IR light,” explained Noda. “We used a fi lter to isolate the signal shifts produced by ants from those created by environmental light changes. Power consumption is less than 50 mW per node, with 90% of that feeding the LED.” Initial results show that the activity of a nest is typically periodic, with steady activity during the night and almost none in the daytime. “The most interesting intervals are where this steady activity builds up and slows down,” said Altshuler. “We already have a preliminary size distribution of activity bursts that can be interpreted in terms of theories involving self-organization.” The team hopes to measure the activity of ants in a trail leading to and from the nest. “We plan to learn how perturbations travel through a queue of ants and compare the dynamics of ant traffic with that of urban or human traffic, which is a subject of intense research nowadays.” is an important material in the field of magnetic data storage. Che says that the technique can be extended to other targets and that the group is now investigating metal alloys and several dielectric samples. Key to the process is a ytterbium-doped fibre laser (FCPAµJewel) that emits 500 fs pulses with a central wavelength of 1 µm and a variable repetition rate of up to 200 kHz. The scientists found that they could suppress the formation of large (>20 nm) dropletlike particles by limiting the laser fluence at the sample to below 1 J/cm2. This value is thought to correspond to the threshold of strong plasma formation. At first the team ablated its target in a vacuum, but it was the use of different background gases, such as argon and oxygen, that produced the most interesting results. “We achieved a core-shell [Ni–NiO] structure as intended,” said Che. “But the NiO cubes were discovered by accident.” High-resolution transmission electron microscopy conducted at the University of Michigan, US, revealed that the nanocubes were in fact single NiO crystals. This was a surprise, because the team thought that the timescale of the ultrafast laser ablation would be too short for oxidation to occur. Claro Noda infrared (IR) LED, a mirror and a phototransistor. The LED and the phototransistor have a peak emission/sensitivity of approximately 850 nm. “The LED and phototransistor are placed back to back and carefully aligned in an incision within a cylindrical mirror,” explained researcher Claro Noda. “The result is a thin light curtain that propagates over the inner surface of the mirror from the LED to the phototransistor.” The team installed its IR sensor at the entry–exit point of a bibijaguas nest, a leaf-cutting ant that is endemic to Cuba. On entering the nest, the ant steps through a ring and interrupts the light curtain that triggers a count. The key term is “activity” which is defi ned as the number of counts the sensor generates Using simple optical components to quantify the behaviour of ants could help scientists tackle problems such as traffic management, say researchers at the University of Havana in Cuba (Review of Scientific Instruments 77 126102). “Ants show a highly nonlinear, collective behaviour that somehow produces an overall intelligence out of individual simplicity,” Ernesto Altshuler from Havana’s Complex Systems and Superconductivity Laboratory told OLE. “We want to quantify and understand the process of self-organization that produces this overall intelligence. Many authors believe that ant behaviour may teach us robust algorithms that can be used in engineering.” The sensor, developed by Altshuler and colleagues, uses an The sensor in-situ verifying ant activity. M AT E R I A L S Low-power, ultrastable femtosecond laser pulses are ideal for generating nanocrystals with a narrow particle-size distribution, say researchers in the US. What’s more, various structural forms, such as cubes and core-shell combinations, can be produced by ablating in the presence of different background gases (Applied Physics Letters 90 044103). “One of the big advantages of our technique is its simplicity,” Yong Che of IMRA America told OLE. “The nanoparticles are dispersed uniformly on the sub- 14 IMRA Laser pulses make nanoparticles The cubes are single crystals of NiO. strate without aggregation.” According to Che, the technique is independent of the substrate material and no heating process is required. This means that nanoparticles can be deposited onto heat-sensitive substrates, such as glass, plastics and polymer films. In this study the researchers decided to ablate nickel, which O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e TECHNOLOGY R&D LASERS Nanosized snow crystals could be an interesting candidate for boosting the coupling efficiency of high-intensity laser energy into matter, say researchers in Israel. The team from Racah Institute of Physics (RIOP) and Soreq Research Center has discovered that sapphire targets coated with snow absorb more than 95% of the incident light compared with approximately 50% for the bare substrate (Appl. Phys. Lett. 90 041501). The experiments were performed using a Ti:sapphire laser emitting 150 fs, 40 mJ pulses at a wavelength of 800 nm. Input The Hebrew Univer sity Snow improves coupling efficiency SEM image of snow on a sapphire target. energy and reflected light were monitored using photodiodes. Bandpass filters were used to isolate the laser light and photodiodes were fitted with a diffuser to average any slight differences in alignment. The laser target substrates with different textures. A molybdenum sample with a rough surface produced snowflakes measuring several microns, whereas a smooth sapphire target gave much smaller clusters in the 10–100 nm range. Zigler and his team discovered that the large flakes behaved as solid targets in their own right and failed to enhance the absorption of incident laser radiation. In contrast, the team believes that the smaller clusters were highly ionized, which helped to increase the laser absorption from 58% for a bare sapphire surface to 97% when it was covered with snow. was scanned from shot to shot so that each pulse was exposed to a fresh area of the sample. The snow clusters were grown on the substrate by injecting water vapour into a vacuum chamber at less than –70 °C. “The main problem was producing a snowflake with dimensions in the range of several angstroms,” Arie Zigler, head of RIOP’s high-intensitylaser laboratory, told OLE. “This was necessary to allow the laser radiation to penetrate through the entire diameter of the snowflake’s characteristic branch.” To vary the size of the snow crystals, the team used target MICROFLUIDICS Researchers at the Hungarian Academy of Sciences are using light to control the velocity of liquid flowing through tiny pores by incorporating a photoconductive material into the channel structure. Ideal for microfluidic systems, the technique exploits the concept of electro-osmosis and relies on changes in the local electric field to modulate the flow (Appl. Phys. Lett. 89 263508). “We can use light to switch the flow on and off and to change the direction of flow at a junction,” Pal Ormos, director of the Institute of Biophysics, told OLE. “Light is easy to handle and brings an additional degree of freedom to microfluidic systems.” The system works by using O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e light to manipulate the local electric field, which in turn affects the electro-osmotic driving force and changes the flow rate. In simple terms, illuminating the channel with light reduces the flow rate. To test its concept, the team built a 0.1 × 0.2 × 10 mm microfluidic channel. The structure was formed by placing a polydimethylsiloxane top plate, prepared using soft lithography, over a glass slide coated with a 200 nm-thick photoactive layer of cadmium sulphide (CdS). “Cadmium sulphide absorbs across a broad spectrum from 550 nm down to below 400 nm and can be excited effectively with a mercury lamp,” said Ormos. “To avoid exciting the CdS layer during observation, we use a red (600 nm) LED source to view the process.” The team captured the flow of water seeded with 2 µm-diameter polybeads on video and analysed the flow field using particle-tracking velocimetry. By illuminating the photoconductive bottom of the microchannel for 30 s, the researchers were able to reduce the flow velocity by more than a factor of five, from 45 to just 8 µm/s. Ormos adds that 30 s was simply a convenient time interval for the flow measurement. It turns out that the velocity transition time is actually closer to 1 s. Looking at potential applications, light-activated switching Hungarian Academy of Sciences Light modulates electro-osmotic flow The researchers used a 3D finite element method to model the behaviour of an optically controlled Y junction. could play a key role in helping to speed up mixing in tiny channels. “Mixing is a great problem in microfluidics as the flow is always laminar and the rate of mixing is limited by diffusion, which is slow,” Ormos said. “One idea is to use light to change the flow patterns in microscopic reaction chambers.” 15 TECHNOLOGY R&D/PATENTS FIBRE LASERS A bismuth-doped fibre can act as a saturable absorber (SA) and extend the lasing wavelength range of ytterbium-doped fibres to 1200 nm, according to researchers at the Russian Academy of Sciences. Q-switched pulses produced at this wavelength are suitable for micromachining and frequency doubling brings medical applications into play (Optics Letters 32 451). “Bi-doped glasses exhibit broadband luminescence in the near-infrared region,” researcher Vladislav Dvoyrin told OLE. “Depending on the glass composition, it could be up to 400 nm FWHM covering the entire silica transparency region from 1 to 1.7 µm. Such glasses are therefore very promising for creating broadband amplifiers for fibre telecommunication lines and tunable or femtosecond lasers.” Inserting a fibre SA into the cavity of a fibre laser is a simple way to construct an all-fibre pulsed laser. Knowing that Bidoped fibres have a broad absorption band at 1 µm that overlaps Images: Russian Academy of Sciences Bismuth boosts all-fibre lasers The team (left to right): Dr V Mashinsky, L Bulatov and Dr V Dvoyrin. This image shows luminescence (red) from a Bi-doped fibre under visible light excitation. The output beam is excitation light that has not been absorbed. well with the Yb luminescence band, Dvoyrin and colleagues decided to use these fibres as SAs for Q-switching Yb-fibre lasers. The team investigated two configurations. The first Yb-Bi double-cavity laser comprised a Yb-doped phosphosilicate laserfibre fusion spliced to a Bi-doped aluminosilicate fibre using a fibre-Bragg grating. A diode laser emitting at 975 nm optically pumped the Yb-doped fibre. “At 1066 nm, the Yb-Bi laser produced pulses with energies of up to 140 µJ, peak powers up to 100 W and pulse durations could be minimized to 400 ns,” said Dvoyrin. “We demonstrated fre- quency doubling at 1066 nm and also made a pulsed fibre Raman laser at 1256 nm pumped by a Yb-Bi laser.” In the second configuration, the team spliced a piece of Bidoped fibre to the other end of the Yb-doped fibre. This second Bidoped fibre acted as an amplifier and allowed the team to generate Q-switched pulses. “An additional fibre-Bragg grating was spliced to the output of the second Bi-doped fibre to reflect the pump backward,” said Dvoyrin. “We used the second piece of Bi-doped fibre as an amplifier because only a small part of the Yb lasing power (the pump in this case) was absorbed in the first piece of Bi-doped fibre.” According to Dvoyrin, this produced lasing between 1150 and 1200 nm. “At 1160 nm we report a pulse energy up to 10 µJ, peak power up to 5 W, pulse duration approximately 1 µs, a repetition rate between 10 and 100 kHz and an average power up to 500 mW, with an efficiency of around 10%,” he said. “We also saw a stable modelocked Q-switched mode with duration of a single peak in a packet less than 1 ns. Frequency doubling at 1160 nm was possible.” Inspired by its initial fi ndings, the team from the Fiber Optics Research Center now plans to increase the pulse energy up to 1 mJ, shorten the pulse duration to 100 ns and develop Bi-doped fibres capable of producing lasing action beyond 1200 nm. “We have also licensed our Bidoped fibre technology,” revealed Dvoyrin. “Yb-Bi lasers are of great practical interest and Bi-doped fibres seem to be the best fibre SAs for Yb-fibre lasers at this time.” PAT E N T S LICENSING BIOLASE teams up with P&G for consumer applications BIOLASE Technology, the US maker of dental lasers, has signed a definitive license agreement with The Procter & Gamble Company (P&G). The terms of the deal grant P&G rights to certain BIOLASE intellectual property for use in the development of consumer products in a number of different areas. The agreement explains that P&G will pay BIOLASE royalties based on product sales, milestone payments and $250 000 quarterly payments until the first product is launched – a portion will be credited against future royalties. BIOLASE will file further details of the agreement with the US Securities and Exchange Commission. “This agreement with P&G opens the door for BIOLASE to participate in the consumer market alongside a proven leader in consumer products,” said BIOLASE’s president and chief executive officer Jeffrey Jones. “We look forward to P&G bringing to the market new consumer products through this relationship.” SE TTL E M E NT Fibre firms announce ‘amicable’ settlement of year-long dispute OFS Fitel, Furukawa Electric Company of North America (FENA) and Nufern say that they have amicably settled the patent litigation that was brought by OFS and FENA in the US District Court LED giants Osram and Philips for the District of Connecticut. agree to cross-licence patents In a statement announcing the settlement, the Osram and Philips have signed a patent crossparties say that they are pleased to resolve the licence deal that involves the mutual licensing dispute, after over a year of litigation, on fair and of patents for inorganic and organic LEDs. The reasonable terms. agreement covers patents held by Philips and The terms of the settlement remain its US-based subsidiary Lumileds, as well as confidential although the arrangement those held by Osram and its subsidiary Osram Opto Semiconductors. “We expect this to put us does include a licence to Nufern under US in an even better position to use LED technology Patent Numbers 4,909,816 (Optical fiber to serve the demands of the market,” commented fabrication and resulting product); 4,666,247 (Multiconstituent optical fiber); and 5,949,941 Rüdiger Müller, president and chief executive (Cladding pumped fiber structures). officer of Osram Opto Semiconductors. To search for recently published applications, visit http://www.wipo.int/pct/en/ and http://ep.espacenet.com. 16 O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e MATERIAL S PROCE S SING Laser water jet cools and cuts in the material world After 10 years in the making, Synova’s water-jet-guided technology is being used to cut, drill, grind and dice materials as varied as gallium arsenide and polycrystalline diamond. Jacqueline Hewett catches up with Synova to find out the advantages of the approach. Wet cut versus dry cut Synova was established in 1997 with the aim of commercializing the water-jet idea developed by the fi rm’s founders in the early 1990s at the Federal Institute of Technology in Lausanne, Switzerland. Today, 10 years later, the fi rm has 60 employees and subsidiaries in the US, Japan, Korea and China. “The original technology was developed to decrease heat damage during laser dentistry,” Tuan Mai, Synova’s director of process development told OLE. “But we soon realized that using a water jet opened O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e 200 µm All images: Synova The micromachining market is already crowded with sources such as solid-state and fibre lasers vying to supplant traditional methods. One company backing a different approach and hoping to capture a significant market share is Synova, which is pioneering water-jet-guided laser technology. Synova is confident that its patented LaserMicroJet technology, which involves directing a laser beam into a thin water jet, has a number of significant advantages over classical laser cutting such as: no heat-affected zones, parallel kerfs and the ability to cut thick and hard materials (see box p19). And it seems that the industry is starting to take note when you look at the fi rm’s track record over the last nine months. On the back of CHF10 m ($8.1 m) of venture capital funding received in August 2006, Synova has opened two US micromachining centres (MMCs) in Boston and Silicon Valley to promote its technology and fuel its adoption. MMCs are also scheduled to open in Korea and Japan in March. In terms of orders, Vishay, a maker of discrete semiconductors and passive components, placed a follow-on order in September 2006 for a laser-dicing system. Then in January, Synova secured two orders from Korea – one for a stencilling system that will be used in OLED mask manufacturing, and the second for a system that will perform thin-wafer edge grinding. 500 µm 500 µm Synova has exploited the advantages of its LaserMicroJet technology to produce clean and parallel cuts in a range of materials. The images here show the cutting of marble (top left), OLED masks (top right), medical stents (bottom left) and cubic boron nitride (bottom right). up new applications for industrial laser machining thanks to its many advantages over traditional techniques.” The basic idea is simple: take one laser beam and couple it to a pressurized water jet. This sounds good in principle, but as light and water are not natural bedfellows, it is easier said than done. Synova’s key technology is a coupling unit (see diagram p18) that forms the heart of its modular LaserMicroJet product line. The unit passes a laser beam through a water chamber where it is focused onto a nozzle. The laser is then contained inside a water jet by total internal reflection and guided to the workpiece where it ablates material by heating. The water jet cools the workpiece between laser pulses and expels molten material from the cut. In comparison, during dry laser cutting, the laser is focused directly onto the workpiece, and the beam has a conical shape between the focusing lens and the focal point. The beam ablates the material by heating at the high-intensity focal point. An assist gas, coaxial to the laser beam, removes molten material. Each LaserMicroJet product has three key separate components: a laser source, a water pump and a coupling unit. The laser is typically a pulsed solidstate source such as an Nd:YAG emitting at 1064 nm, or a fibre laser emitting at approximately 1070 nm. “The absorption properties of water at different wavelengths dictate the choice of laser,” explained Mai. “For example, you cannot use a CO2 laser with our technology because the water absorption is so high you would boil the water. However, you can use a second harmonic at 532 nm and a third harmonic in the ultraviolet at 355 nm.” Average laser powers can range from 50 to 200 W; pulse durations from the nano- to microsecond scale and pulse repetition rates from 500 to 50 kHz depending on the pulse duration. The laser source can be remote from the machining system as 17 MATERIAL S PROCE S SING laser focusing lens window working range (depth of field) water chamber conventional laser beam (divergent) water-jetguided laser (cylindrical) nozzle working range Synova focal point Synova a flexible 100–200 µm-core-diameter fibre delivers the beam into the coupling unit. “This means that we can use multimode lasers and don’t have any problems with beam astigmatism,” commented Mai. “The beam is homogenized inside the water jet and we see a top-hat profi le that is very good for cutting. It also means that you can remove the fibre and plug it into a second laser if you want to test different sources.” The pump delivers a constant water flow with pressures ranging from 2 to 50 MPa. “The water must be clean and free of contamination and particles because we use the water jet as a waveguide, so it must be transparent and stable,” said Mai. “We deionize and degass the water to ensure that there are no perturbations in the jet.” In the coupling unit, Synova uses a series of optics to image the end of the delivery fibre onto the water-jet nozzle. Made from diamond or sapphire, the nozzles are interchangeable and are available in diameters ranging from 25 to 150 µm. Mai explains that in general, the working distance is 1000 times the nozzle diameter. This means that a 50 µm nozzle gives a working distance of 50 mm and a corresponding kerf width of 50 µm. Synova’s LaserMicroJet product line The diagrams on the left compare a dry (left) cut using a conical beam and a water-jet (right) cut using a parallel beam. The instrument on the right is a Synova laser-dicing system. has four family members: dicing, edgegrinding, stencilling and cutting systems. “Today we mainly concentrate on so-called micro-applications. That is the niche for us at the moment,” commented Mai. “Our technology can be adopted wherever a normal laser is being used.” According to Mai, one up-and-coming market is wafer dicing, which typically relies on diamond blades. The company has used its technology to successfully dice silicon, gallium arsenide and germanium wafers, as well as silicon carbide (SiC) and sapphire. Important advantages include the absence of a thermal load. The kerf can be close to the die to increase the number of chips per wafer and give a higher die-fracture strength. Synova says that one of the most significant issues with dicing SiC wafers is blade wear – LaserMicroJet technology removes this worry and lowers the downtime and corresponding cost of ownership. Synova has demonstrated through-cutting of 380 µm thick SiC wafers with a kerf width of 45 µm and cutting speed 40% higher ÀÞÃÌ>>À / #OMPRESSION0ACKAGING ÀÊÜ >̽ÃÊvÀ>}iÊÊÞÕÀÊÜÀ`t ÀÞÃÌ>>À/Ê «ÀiÃÃÊ*>VÃÊ>ÀiÊÌ iÊÕÌ>ÌiÊÃÕÌÊvÀÊ ÞÕÀÊiÝÌÀiiÞÊÃiÃÌÛiÊ>`ÊvÀ>}iÊ« ÌVÊ«À`ÕVÌðÊ/ iÊÊ `ÕÀ>LiÊÕÌiÀÊà iÊiÃÕÀiÃÊÌ iÊÃ>viÌÞÊÜ iÊÌ iÊÃ`iÊvÊÌ iÊ «>VÊ}iÌÞÊ«ÀÌiVÌÃÊÞÕÀÊ«À`ÕVÌÊLÞÊi>ÃÊvÊ>LÀ>ÃÛiÊÊ i>ÃÌVÊw°Ê ÀÞÃÌ>>ÀÊ}Õ>À>ÌiiÃÊÌ >ÌÊÞÕÀÊ«À`ÕVÌÊÜÊÌÊÊ LiÊ>vviVÌi`ÊLÞÊÕÌ}>ÃÃ}ÊÀÊiVÕ>ÀÊÌÀ>ÃviÀiViÊÕ`iÀÊÊ Ó{nÊ®°Ê"ÊÌ«ÊvÊÌ >ÌÊÌ iÊwÊÃÊ>ÃÊÌi>ÀÊÀiÃÃ>Ì°ÊvÊ>Êà >À«ÊÊ LiVÌÊÜÕ`Ê«ÕVÌÕÀiÊÌ iÊw]ÊÌ iÊ«ÕVÌÕÀiÊÜÊÌÊ«À«> }>Ìi]ÊÌ ÕÃÊii«}ÊÞÕÀÊ«À`ÕVÌÊÃ>viÞÊÊ«>Vi°ÊÊvÕÀÌ iÀÊL}Ê «ÕÃ\ÊÌ iÊÌÀ>ë>À>ÌÊVÌ>iÀÊ>ÜÃÊÞÕÊÌÊÛiÜÊ>`ÊëiVÌÊ ÞÕÀÊ«À`ÕVÌÃÊÜÌ ÕÌÊÃÕLiVÌ}ÊÌ iÊÌÊiÛÀiÌ>Ê iÝ«ÃÕÀi°ÊÊ ÀÞÃÌ>>ÀÊ«>VÃÊV>ÊLiÊVi>i`ÊÌÊ >ÃãääÊ>`Ê /"É>>ÊÃÌiÀâi`Ê>`ÊLiV>ÕÃiÊvÊÌ iÊi>ÃÌVÊwÊÀ}ÃÊ>ÀiÊ ÀiÛ>Li]ÊÌ iÊ«>VÃÊV>ÊLiÊÀiVi>i`Ê>ÃÊÜi° /«>Ê6iÀ«>}Ê6Ê ® i>\ÊvJÌ«>° Ìi\ʳΣÊÓxÓÊÓ{xÊÓÇnÊÀÊÓx® 18 /Ê*,"1 /Ê*,"/ /", O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e MATERIAL S PROCE S SING LaserMicroJet facts Synova believes that coupling a water jet and a laser beam together has revolutionized the field of precision cutting. The inherent differences between water-jet-guided and conventional dry-laser technologies are said to be responsible for the variations seen in the quality of the final cut. Synova lists the following as advantages of its LaserMicroJet technology: O The water jet removes heat between incident laser pulses and avoids the introduction of defects caused by heating such as oxidation or microcracks within the sample. O The cut is exceptionally clean. Molten and condensed materials are washed away by the water. An additional thin water film generated on the workpiece prevents further contamination through redeposition. O The ablation products are bound to the water in such a way that no hazardous materials (such as toxic gases) are emitted. This is an important advantage for dicing gallium arsenide wafers. O The water jet exerts a low mechanical force on the workpiece (less than 0.1 N) – much smaller than the force that is applied by an assist gas. O The diameter of the laser beam is determined by the diameter of the water jet. These conditions allow a cutting precision as low as 1 µm. O There is no focal point between the workpiece and the nozzle. The quality of the cut does not vary with working distance. O The water jet guides the laser down to the bottom of the kerf and high aspect ratios can be achieved during cutting. The cut edges are parallel. O There is low water consumption of 1 l/h at 300 bars. than a diamond saw blade (4.6 mm/s). Another significant market where Synova has already seen some traction is manufacturing OLED masks. “We have been able to produce long and narrow slots with a tapered profile,” said Mai. “In one example these were 55 mm long, 100 µm wide at the top and 50 µm wide at the bottom. The pitch between these can be as little as 150 µm.” Producing medical stents, which are used to open blocked passageways such as arteries, is another area where Synova believes its water-jet approach gives it the upper hand. “These are mostly manufactured using classical laser cutting and can require postprocessing steps,” said Mai. “Many stents are made from memory-shape materials such as Nitinol, which is very heat sensiO L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e tive. Using a 30 µm nozzle, the pitch and size of the features can be made very small, and using a water jet avoids problems such as heating. There is no structural change in the material and no oxidation.” Finally, Mai believes that Synova is the only player that can cut hard materials with high quality, good/superior speed and high aspect ratio. Materials falling into this category include polycrystalline diamond on a tungsten carbide substrate and cubic boron nitride (CBN). “Using 532 nm light, an aver- age power of 60 W and a water-jet diameter of 50 µm, we have cut 3 mm-thick CBN with a speed of 5 mm/s and produced a smooth, parallel clean cut with a sharp edge.” Boasting a list of advantages as well as a diverse range of applications, the technology, Synova believes, has what it takes to challenge all others in the materialsprocessing market. As the fi rm continues to expand and promote its technology, the term “water-jet guided laser” certainly looks like becoming more commonplace. Q LASER OPTICS IR OPTICS UV-NIR, Nd: YAG UV Grade High Power Gaussian Mirrors Internet Stocklist ZnSe, ZnS, CO2 Ge, Si, CaF2, BaF2, Sapphire Diffractive Optical Elements Gratings and Monochromators FIBRE OPTICS OPTICAL FILTERS Fibre Patchcords Collimators Splitters, WDM CWDM, Isolators Fibre Cable Sapphire Cable DETECTORS IR PbS/PbSe, MCT Thermopile, Pyroelectric Single Chip or Array with or without TEC and/or Integrated Amplifier LASER DIODES Pulsed, CW, Pigtailed, Receptacled, Spectroscopic, QCLs, VCSEL, DFB, Lead Salt, Optional TECs, Arrays, Drivers and Fibre Coupling UV Filters, NBP LWP, SWP, Custom Volume Bragg Gratings Fluorescence Colour Imaging Raman Spectroscopy DETECTORS UV-vis UV SiC with Integral Filters and TIAs vis Si, NIR InGaAs Colour Sensors Position Sensing Detectors OPTOELECTRONIC MEASUREMENT Proximity, Light Barrier Laser Alignment, Colour Non-contact Fibre Thermometer ACCESSORIES Laser Safety Goggles IR Converter Cards/Screens IR Camera Viewers www.lasercomponents.co.uk L ARGE - SCALE OP TIC S UK produces giant camer One of the world’s largest cameras to be built for astronomy was transported to the European Southern Observatory (ESO) in Chile in February. It will be the eyes of VISTA (Visible and Infrared Survey Telescope for Astronomy) – a new 4 m-class telescope that will survey the sky in the southern hemisphere in the scientifically important spectral region of 1–2.5 µm. The telescope’s camera is almost 3 m long, uses large optics (i.e. its entrance window is 1 m in diameter) and weighs 3 tonnes. These features make it a real colossus among optical cameras, and its demanding performance requirements (see box) have pushed large-optics technology to the limit. The design required the finished instrument to be portable – this means that it can be lifted on and off the telescope by a crane as a single assembly. In total, the camera has taken four years to design and build, and uses components sourced from suppliers across Europe and the US. On the move The camera had to be built on a dedicated handling stand. The stand and the camera’s mounting had to be made strong enough to allow for the earthquake-prone environment of Chile. This feature was also useful when it came to transporting the camera. It was just possible to make the camera and its stand fit within the largest cargo container allowed on a Boeing747. As with other large optics, such as mirrors for astronomical observatories at remote sites, this journey to Chile was particularly risky for the fragile and high-value optics of the camera, especially as the last part of the trip was along a very rough dirt road in the Atacama desert. Because of such concerns, many previous instruments have been shipped in several parts, but this has other disadvantages. In this case, the bold decision was made to ship the instrument complete. This was made possible partly thanks to the built-in strength of the earthquake-proof assembly and partly by following the approach of the space industry for shipping satellite optical pay loads of a similar size to launch sites. The camera arrived safely at the ESO at 20 the beginning of February and members of the team have spent a month installing it and carrying out initial tests. This included the delicate operation of lifting the portable camera off its stand by crane and raising it into the observatory dome to finally unite it with its telescope. Various other tests of VISTA’s systems and software will follow and the camera’s first use on the sky should start this autumn. There are plans to take test images of so-called guide stars to set up VISTA’s active optics system and verify its imaging performance. After that, the VISTA science programme will use the wide-angle, high-sensitivity properties of the camera and its optics to make new surveys for infrared (IR) objects across the sky of the southern hemisphere. The aim is to look deeper into the universe and yet be able to complete the searches faster than ever before. Pushing the limits of large optics The camera uses the world’s largest focalplane array of detectors measuring 0.3 m in diameter and incorporates wavefront sensing detectors for the active optics control of the telescope. The term active optics refers to the compensation of errors such as focus, alignment and aberrations, which are corrected by adjusting some components on the actuators. The two telescope mirrors are made active in this way, using signals derived from the camera wavefronts. The focal plane is so large because VISTA has a relatively wide-angle field of view, imaging an area of sky that is three times the diameter of the Moon. The cryogenic detector array comprises 16 IR-detector modules from Raytheon, US, giving 67 Mpixel in total. The wavefront-sensing system was built at the University of Durham, UK, using charge-coupled devices from e2v. Packing such a large format of detectors into one camera produces multiplexing challenges for supplying power, clocking of read-outs and extracting signals at low noise. The camera has a significant amount of electronics on board to overcome these problems, including five large racks mounted around its outer surface. In VISTA project An infrared, 67 Mpixel, 3 tonne camera has been successfully installed on the VISTA telescope in Chile. Martin Caldwell from the UK’s Rutherford Appleton Laboratory explains how the instrument pushed the limits of large-scale optics. The camera was united with the VISTA telescope (left) after a tre array of detectors measuring 0.3 m (bottom) and many other cus sustained operation, wide-field images can be produced every 10 s leading to data rates of up to 1 Tb per night of observing. A giant filter wheel that is 1.4 m in diameter sits just above the focal plane (see diagram). The wheel needs to be large as it has to house up to seven arrays of spectral filters. Each of these arrays covers one waveband and is approximately 0.3 m in size to fully cover the detector array. The science wavebands currently installed are centred around 1.0, 1.2, 1.6 and 2.15 µm, with bandwidths of 0.1–0.3 µm. Developed by the UK Astronomy Technology Centre (UKATC), the challenge with such a large, moving component was to create a cryogenic mechanism and motor to deal with the large inertia involved when swapping rapidly between different filter sets. Change-over times are on the order of 10 s. The main camera optics comprises a group of three lenses, each 0.6 m in diameter. The lenses correct aberrations and allow a normally narrow-field two-mirror telescope to be used over a wide field of view. The lenses are the maximum size that can be manufactured from IR-transmitting silica. They are O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e ra for infrared astronomy Ruther ford Appleton Laborator y, UK detector array modules (infrared and CCD) filter barrel lens barrel baffle tube pressure window cryostat vessel electronics rack telescope structure and mirrors Ruther ford Appleton Laborator y, UK VISTA background and performance ek across the Atacama desert (top middle). It uses a focal-plane stom components sourced from Europe and the US (top right). fabricated by Sagem in France and built into a cryogenic lens-barrel by UKATC. A significant challenge was making the lens mounts stiff enough to limit the flexure effect when the camera orientation varies as the telescope tips around the sky, and yet compliant enough to cope with the large thermal strains that occur during cooldown and warm-up. Both effects are exacerbated as lens size increases due to the low conductivity of silica, and their control is critical to the quality of the final image. Above the lenses is a large cryogenic baffle tube that blocks ambient thermal emission from the observatory and atmosphere, which would otherwise swamp astronomical sources emitting in the 2 µm spectral region. Because the system is wide-field and relatively fast (~F/3), it is not possible to use the conventional approach where an internal cold pupil stop would fully block this background emission. Instead, blocking is achieved by making the cold baffle tube of sufficient length to prevent direct views of the ambient surround and by making its internal surfaces sufficiently absorbing. This creates another problem. The baffle O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e VISTA is a £36 m project funded by grants from UKATC and the infrared camera was provided by a UK consortium led by the Rutherford the UK Department of Trade and Industry’s Appleton Laboratory. Joint Infrastructure Fund and the Particle VISTA’s key performance statistics are: Physics and Astronomy Research Council (PPARC). Queen Mary, University of London, is O field of view – 1.65° diameter; the lead institute of the VISTA consortium. O image quality – 0.5 arcsec; The project forms part of the UK’s O spectral range – 0.9–2.5 µm; subscription to ESO, and VISTA will be an ESO O sensitivity (5-m level, 15 min exposure – 20th magnitude source. telescope. The project is managed by PPARC’s must be reflective in the thermal wavelength region of approximately 10 µm, such that heat radiated by the window to the baffle is efficiently returned to the window to prevent it from becoming too cold and misting up. The answer is to use specially designed reflective baffle vanes with a dichroic coating that absorbs in the 2 µm region, but reflects in the longer thermal wavelength region. Under test, this solution, which includes a coating developed by Reynard Corporation, US, offered sufficient stray-light blocking as well as the correct thermal balance between baffle and window. The required baffle length makes the camera’s cryostat relatively long and leads to its front window having an aperture of approximately 1 m. Such a large vacuum window, fabricated from 8 cm-thick IR-transmitting silica for strength, and to meet stringent optical quality requirements, could only be made with the collaboration of three manufacturers: Heraeus, Germany, which produced a large boule of homogenous Infrasil glass; Corning, US, which flowed-out the glass to the required size; and Sagem, France, which performed the final polishing using ion-beam techniques to remove the residual inhomogeneity effects and arrive at a transmitted wavefront error of approximately 100 nm. One final challenge was the optomechanical design and producing a structure to hold all of the cryogenic items (detectors, filter wheel, lenses and baffle, totalling 0.7 tonnes) on a thermally isolating cradle in a cryostat vessel. This structure needed to be sufficiently stiff to limit flexing effects and yet compliant to cope with thermal cycling, while allowing significant cooling power to be applied and last, but not least, having the ability to survive earthquakes. Particularly challenging were the issues of controlling the detectors and the optics focus positions to within less than 10 µm planarity across the large focal plane and making this stable enough with respect to the telescope. Q Martin Caldwell is an instrument systems engineer within the Space Science and Technology Department at Rutherford Appleton Laboratory. For more information, see www. sstd.rl.ac.uk or e-mail m.caldwell@rl.ac.uk. 21 Project1 7/2/07 09:46 Page 1 MEDICAL RE SEARCH Nerve stimulation gets infrared light treatment Rather than popping pills, patients of the future may find themselves relying on infrared (IR) nerve stimulation to tackle a range of medical conditions. Increasingly, scientists are looking at the body’s neural network as a way of providing localized treatment. The concept may sound farfetched, but vagus nerve stimulation is available today as an alternative to Prozac for managing depression. Neurons are typically activated using electricity, but researchers have recently discovered that pulses of IR light can also stimulate nerves. To help drive this work, Aculight has teamed its optics know-how with the research community’s medical knowledge and come up with an investigative tool for use in the laboratory. In simple terms, the fibre-coupled laser device can be thought of as a neurological circuit tester. “You stimulate the nerve at one location and observe what happens at the other end to see if the pathway is open,” Mark Bendett, Aculight’s director of product development, told OLE. “In a Petri dish you can see how a signal propagates through adjacent cells.” The firm is collaborating with Northwestern University, US, on a programme to optically stimulate the cochlear nerve, which plays a key role in hearing. Today, cochlear implants are electrically activated and feature approximately 10 channels that help to recreate the sensation of hearing, but the technology appears to have hit a barrier. “Right now in a cochlear implant, the real limitation is current-spreading,” said Bendett. “Even if you put 100 electrodes into the cochlea, most of them would crosstalk and you wouldn’t gain any more fidelity.” It turns out that one of the big advantages of optical stimulation is the technique’s high spatial accuracy. “You don’t have the problem of current spreading because the process involves photons hitting the target and not electrons, which are conducted by water in the body,” he added. The team expects IR stimulation to offer O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e Aculight Stimulating nerves with pulses of infrared light could help to restore balance, intensify hearing implants and lead to more advanced prosthetic limbs. James Tyrrell talks with Mark Bendett to discover more about Aculight’s role in this up-and-coming research area. Capella: Aculight’s infrared nerve stimulator is intended for use in medical and scientific research. “We believe that this will end up in curative applications.” similar benefits when applied to the ear’s vestibular system. “As we get older our vestibular system degrades, which can lead to a lack of balance,” explained Bendett. “I think that this could be one of the largest complaints that we will see with an aging population.” Origins of the technology Researchers at Vanderbilt University, US, were some of the fi rst to investigate the effect of pulsed IR light on neural activity. “They demonstrated the basic concept using a free-electron laser,” explained Bendett. “You want a wavelength that is absorbed sufficiently to stimulate the nerve without ablating the tissue and it turns out that 1.85 µm is one of those wavelengths.” The group approached Aculight to provide a portable light source. Bendett and his colleagues responded with an engineering prototype based on a diode laser array. Two years later, Aculight released its production version dubbed Capella that could be used straight out of the box. “The current model has a tremendously rich set of features,” said Bendett. “Users can switch between trains of pulses and single and continuous formats using front knob controls.” One of the challenges that the designers faced was the need to balance coupling efficiency with the amount of power on target. “We want to maximize the efficiency of the coupling from the laser to the fibre, but at the same time we need to contain the light to a sub-cellular level of about 10 µm or so,” revealed Bendett. “This can be done using a variety of special optics or tapered fibres, but the trick is to do it cost-effectively.” Aculight offers the Capella in both high- and low-power configurations. “As you would expect, it’s a trade-off between pulse energy and speed,” said Bendett. “We can actually semi-customize the unit to match the application, so if you are working on a smaller nerve and need 23 MEDICAL RE SEARCH less optical power then we can give you sharper rise times.” Although currently an investigative tool, the fi rm expects the technology to evolve into a fully implantable device. “We believe that this will end up in curative applications,” Bendett said. “It’s further down the road, but we can see uses in prosthetic limbs where you might do the stimulation optically and then provide feedback electrically to make the unit touch-sensitive.” With so many applications on their hands, Bendett and his co-workers are busy trying to figure out which ones will really benefit from optical stimulation. “I was at a neural interface conference last year where a Parkinson’s patient with an electrical deep-brain stimulator stood up in front of the audience,” he recalled. “The patient could turn up the stimulator so that it completely stopped their tremors, but at this level they were then unable to speak.” This side-effect is a symptom of electrical crosstalk. “The current is hitting the cells that it is supposed to, but it’s also hitting those that it shouldn’t,” explained Bendett. “It’s exactly this kind of application where we see optical systems coming into play.” Aculight’s business strategy for nerve stimulation is based on intellectual prop- Capella specifications Parameter Tissue-penetration depth Stimulation duration Stimulation repetition rate Maximum duty factor Emission wavelength Maximum optical pulse energy Optical fibre diameter Fibre connector Power requirements Dimensions Weight Cooling Triggers Value 300–600 µm 10 µs – 20 ms 0.4–1000 Hz 5% 1850 nm (approx.) 5 mJ (at 1 ms) 200–600 µm SMA 115 or 240 V 12.5 × 13.25 × 4.75 inch 11.5 lb Air cooled Internal and external lator into the hands of researchers. “We would like to disseminate the technology across as many clinical platforms as possible,” said Bendett. “And the easiest way for us to do that is to put it out to dozens of research groups who can then work with us on the technology.” The fi rm already has National Institutes of Health grants with the Northwestern and Vanderbilt universities, and aims to be flexible in terms of providing users with the technology. “Currently we have a total of six universities testing different nerves and techniques with our laser,” explained Bendett. “Ultimately, to get a good idea of the application landscape we expect three to four times this number of institutions to trial the device.” Today, the unit is aimed at the research market and is registered as a laboratory instrument. “As soon as we start working on humans we will have to go through the US Food and Drug Administration approval process,” said Bendett. “Realistically, we will probably do this in conjunction with other companies in the medical field rather than on our own.” Q erty. “We are positioning ourselves to be a sort of clearing house for the technology,” said Bendett. “We have an exclusive licence from Vanderbilt University and would like to be involved as an OEM [original equipment manufacturer] for the hardware.” For more information contact mark.bendett@ The fi rm is keen to get its optical stimu- aculight.com. YOUR CHOICE FOR PUBLICATION FASTER THAN THE SPEED OF LIGHT* Journal of Optics A: Pure and Applied Optics Submit your next research paper to Journal of Optics A: Pure and Applied Optics to benefit from: • fast publication times (*the average receipt-to-first-decision time for papers in 2006 was just 42 days) • free use of colour and multimedia in the online version of your paper • easy web-based submission and article-tracking facilities To find out more, visit www.iop.org/journals/jopa. An official journal of the European Optical Society Image: Colour coded x-y displacements caused by rotation of a speckle pattern around its centre P Somers and N Bhattacharya 2005 Journal of Optics A: Pure and Applied Optics 7 S385–S391. 24 O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e PRODUCT GUIDE Imaging colorimeters give advanced options CCD-based instruments can provide accurate measurement of spatial colour and luminance information for displays, instrument panels, light sources and luminaires. Sean Skelley, Doug Kreysar and Kevin Chittim weigh up the options when buying imaging colorimeters. The need for speed O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e imaging lens CCD detector interline transfer neutral density filter wheel instrument control, data acquisition and image-processing system Radiant Imaging colour filter wheel full frame interline transfer with colour filters Fig. 1 (left): a schematic of the main functional elements of an imaging colorimeter. Fig. 2 (right): commonly used CCD types in imaging colorimeters include full frame, interline transfer and interline transfer with integrated colour filters. The type of CCD used will impact on the instrument’s performance. luminance data at a number of viewing angles. This technique is accurate but slow and therefore used to collect data only from a small number of points on the source over a limited range of angles. This makes it possible to miss significant features or defects in the product’s output. Imaging colorimeter basics Imaging colorimeters were developed specifically to address the limitations of prior instrumentation. The main components of an imaging colorimeter are: an imaging lens; a set of colour fi lters; a chargecoupled device (CCD) detector; and data acquisition and image-processing hardware/software (see figure 1). Some instruments may include neutral-density fi lters and a mechanical shutter. The system acquires an image of the device under test through each of the various colour fi lters. This is then processed using previously determined calibrations to deliver accurate data about the source’s colour and luminance as a function of spatial location. For example, in a single measurement, an imaging colorimeter can measure the luminance and colour of every pixel in a display simultaneously at a given viewing angle. The instrument can also be mounted on a goniometer to automate these measurements at different viewing angles. Because an imaging colorimeter simultaneously samples multiple points from a source, it is inherently faster than techniques based on spot measurements. In addition, simultaneously measuring the entire surface of a source or display makes the instrument useful for gauging colour and luminance uniformity, as well as identifying very small defects. An imaging colorimeter can even assess display characteristics, such as distortion and focus quality. The ability to render a processed image of the display also can help to reveal subtle features for qualitative analysis by a human operator. Current commercially available imaging colorimeters come in a variety of configurations. In terms of hardware, the most important differentiators are the type of CCD and colour fi lters. Understanding how these components impact on performance is essential when specifying an imaging colorimeter. V For many types of FPD, human visual inspection is by far the most common method to monitor production quality. Specifically, units are removed from the production line and inspected for colour and brightness uniformity, and defects such as dead pixels, for example. The primary drawback of this manual-inspection approach is speed, since it cannot be integrated directly into the assembly line. Human inspection is subjective and can easily vary from operator to operator. This non-quantitative approach also makes it difficult to enforce standards throughout the component vendor supply chain. A similar speed issue applies to LED manufacture. The final performance of an LED-based illumination system depends on the exact angular and colour output characteristics of the source. However, LEDs are made in high volume so any such characterization must be accomplished quickly and add little incremental cost. Metrology instruments for both of these applications have been available for many years, albeit with limited capabilities. An established method is to mount a spot photometer or colorimeter onto a two-axis goniometer and sweep the measurement head through various arcs to obtain colour and shutter Radiant Imaging The market for light-emitting products has expanded tremendously over the past decade to include flat-panel displays (FPDs) and high-brightness LEDs for automotive applications. As consumers of these high-volume devices become more discerning about product quality, there is an increasing need for accurate, high-speed metrology equipment to support their development and production. Instrumentation for spatially resolved measurements of colour and luminance is particularly important. This article reviews the basic operating principles and performance trade-offs of one such class of instrument – imaging colorimeters. 25 28/2/07 11:13 Page 1 Hi sp gh ec re s t r RQ om olu O\ tio e ¼ ter n fo r Upgrade headaches? Ocean Optics makes it easy! Upgrading is not something you want to spend too much time on, that’s why we make it easy! Trade-in your RSWLFDO EHQFK GHVLJQ DQG EULQJV ÀH[LELOLW\ LQWR \RXU ODE 7KH EXLOWLQ FRPSRVLWLYHJUDWLQJ DOORZV old spectrometers now and upgrade to an IRU D ZLGH VSHFWUDO UDQJH IURP 2FHDQ 2SWLFV +5&* SUHFRQ¿JXUHG QPDQGWKH+5%HQFKSURYLGHV spectrometer with our SpectraSuite QP ):+0 UHVROXWLRQ 7KLV software at a spectacular price of makes the HR4000CG the ultimate general purpose spectrometer for any ¼ This spectrometer is based on the unique Ocean Optics High Resolution DSSOLFDWLRQ (VSHFLDOO\ LQ FRPELQDWLRQ ZLWK RQHRIRXUEURDGEDQGOLJKWVRXUFHV What to do next: 'HWHFWRUUDQJHQP 86%FRQQHFWLRQ 5HVROXWLRQQP):+0 SL[HOV&&'GHWHFWRU S/N ratio: 300:1 :LQGRZV0DFDQG/LQX[FRP- 506FRXQWVGDUNQRLVH patible user interface software 2. Send back your old spectrometer VWRVLQWHJUDWLRQWLPH 60$RSWLFDOFRQQHFWRU *HWWKLVSDFNDJHIRURQO\¼ 1. Order the HR4000CG & SpectraSuite +31 26 319 0500 info@oceanoptics.eu www.oceanoptics.eu 3ULFHRQO\YDOLGDIWHUDFFHSWHGWUDGHLQ2IIHURQO\DSSOLHVWRWKH+5&*VSHFWURPHWHUDQGLVYDOLGXQWLO$SULOVW Project1 PRODUCT GUIDE CCD choices full frame interline with filters interline Radiant Imaging actual intensity profile measured intensity profile CIE matched filter transmission CIE z Radiant Imaging Virtually all imaging colorimeters are built using one of three types of CCD: full frame; interline transfer; or interline transfer with integrated colour filters (see figure 2, p25). A full-frame CCD is an unobstructed rectangular array of detectors. Electronic charge accumulates in each pixel when light strikes the CCD. Readout occurs by sequentially shifting each row of pixels down into a read-out register until the entire array is cleared. An external shutter prevents light from reaching the CCD during the read-out cycle to avoid image smearing. In an interline-transfer CCD, alternate columns are masked with an opaque layer. During read out, the accumulated charge in each exposed column is rapidly transferred laterally to a non-imaging column where the charge is shifted into the readout register. This allows read out to occur while another exposure is being acquired. Both of these CCD types respond only to incident luminance and cannot measure colour directly. To measure colour, separate exposures must be made through red, green and blue colour fi lters. However, a variant of the interline-transfer architecture has each pixel overlaid with either a red, green or blue colour fi lter specifically for direct colour measurement. There are several important CCDdependent performance characteristics to be aware of, starting with fill factor. When an image is formed on a full-frame CCD, virtually none of the information is lost. On the other hand, a significant percentage of the surface of an interline-transfer CCD is opaque, so image features that fall on this blocked area will not be seen. In practice, interline-transfer CCDs often use a micro- integrated filter 400 600 500 wavelength (nm) 700 Fig. 3 (top): low fill factor can cause important data to be lost, especially when imaging small sources or features. Fig. 4 (bottom): individual colour filters that closely match the system response to the CIE curves can be obtained, but the filters typically integrated directly onto CCDs do not provide a good match. This graph shows the CIE z curve together with the system response using a well-matched filter versus an integrated filter. lens array to focus some of the light that would normally be blocked into the active area. This can increase fill-factor efficiency by up to 70%. The fill-factor problem is further exacerbated by the presence of integrated colour fi lters. Figure 3 shows how missing data can cause erroneous results An image speaks louder than 1000 measurements when the output of a single LED is focused onto a 5 × 5 pixel area of the CCD. Another major difference between CCD types is their dynamic range. The defi nition of a CCD’s dynamic range is the maximum capacity of each pixel in electrons (called the full-well capacity) divided by the RMS dark noise (the number of electrons read from the device with no input light). Full-well capacity increases with pixel size. Full-frame CCDs typically have larger pixels, with full-well capacities of between 200 000 and 700 000 electrons, making dynamic ranges of 14 (16384:1) to 16 bit (65536:1) possible. In contrast, the full-well capacity of most interline-transfer CCDs is in the 10 000–20 000 electrons range, resulting in a dynamic range of 12 bit (4096:1) or less. There are also several practical differences between CCD types. A full-frame CCD requires an external shutter and active cooling to minimize noise while an interline CCD does not. These features add to system size, weight, cost and complexity. An interline-transfer CCD can be read out faster than a full-frame CCD, which could be a consideration in high-speed production applications. Calibrated colour Correlating the colour response of a CCD camera to the human visual system requires measurements to be made in a calibrated colour space, such as the CIE format. This means matching the overall system response to the corresponding CIE colour curves using colour filters. Very close matching is possible by designing external glass fi lters. Unfortunately, the RGB colour filters typically integrated onto Imaging Photometer and Colorimeter LumiCam 1300 For measuring and analyzing displays and panel graphics am n l iC olutio apixe m s g Luigh Re 0.5 me H th 1 wi ! W luminance [cd/m2] chromaticity (xyz, XYZ, u’v’) dominant wavelength [nm] luminous intensity [cd] purity contrast ratio NE O O O O O O 0 0 40 phone +49 89 45 49 43 -0 info@instrumentsystems.de www.instrumentsystems.de WE BRING QUALITY TO LIGHT O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e 27 PRODUCT GUIDE Choosing the right hardware In commercial systems, full-frame CCDs are usually paired with CIE-matched colour fi lters, while interline-transfer CCDs are mated with either CIE-matched fi lters or on-chip fi lters. The full-frame systems are typically the most expensive and the slowest, however they deliver superior dynamic range (up to 16 bit), signal-tonoise ratio and colour accuracy. They are well suited to high-contrast applications such as automotive headlamp evaluation or high-end projector contrast testing. Interline-transfer cameras with integrated colour filters offer low cost and high speed but limited dynamic range (usually 8–10 bit) and colour accuracy. This makes them a better choice for many on-line or at-line production inspection tasks. However, their limited fill factor means that they may not be optimum for examining small-scale features, such as pixel and sub-pixel defects. Interline-transfer systems with CIEmatched fi lters offer a good compromise between cost and performance. With a typical dynamic range of 12 bit and excellent colour accuracy, they deliver enough performance for production testing of FPDs, backlights, projection systems and instrument panels, and are suitable for use with Imaging colorimeters enable advanced metrology. LEDs and other narrowband sources. nitely assess what hardware and software tools are available for a particular system. Calibration In conclusion, imaging colorimetry While hardware choice is important, the accuracy of any imaging colorimeter is instrumentation has developed over the only as good as its calibration. Most manu- past few years to meet the evolving needs facturers’ systems leave the factory fully of manufacturers of displays and other calibrated but the ease with which the user light sources. These quantitative metrolcan perform periodic recalibration can be ogy tools will play an increasingly critical a major differentiator in long-term system role in display production as volumes and consumer expectations increase. performance and utility. Q Typical calibrations include flat fielding, luminance scaling and colour calibration. Sean Skelley is technical support manager, For instance, allowing users to create on- Doug Kreysar is vice-president of operations and site colour calibrations when measuring Kevin Chittim is vice-president of marketing at specific spectra can increase the colour Radiant Imaging. For more information e-mail accuracy of the system. Prospective pur- skelly@radiantimaging.com or visit www. chasers of imaging colorimeters should defi- radiantimaging.com. Radiant Imaging interline-transfer CCDs do not provide a close match to the CIE curves. The resultant colour accuracy is highly dependent on the nature of the source being measured and how the system is calibrated. Accuracy using mismatched filters is usually substantially worse when measuring narrowband sources, such as LEDs. Figure 4 (p.27) shows an example of the spectral mismatch of a colorimeter using integrated filters with the CIE colour curves. TM Optical ILLUMINATOR Components COBRA Millimeter-Wave LINESCAN Photodiodes (DC - 300GHz) Lasers Powerful LED illumination that outperforms halogen and fiber every time • 125, 250 and 500 mm line lengths • Available in red, IR, blue, UV, and white • High level of line uniformity StockerYale Inc. 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O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e PRODU C T S If you would like your company’s products to be featured in this section, please send press releases and images to James Tyrrell (james.tyrrell@iop.org). Line-scan cameras AMS Technologies The new dual-band line-scan camera from Princeton Lightwave is now available through AMS Technologies. Equipped with two independent sensors, the ID line-scan camera can simultaneously image visible (400–900 nm) and infrared (1000–1700 nm) wavelengths. The two images are then automatically spatially and temporally registered. Each sensor provides two analogue output streams that are processed using correlated double sampling and darklevel correction. The streams are converted to 12-bit digital data and buffered into dual-port RAM for synchronization and further digital processing. The camera is ideal for machinevision applications such as inspection in the food industry and sorting different plastic materials in waste-management machinery. www.ams.de UV spot-lamp DYMAX The new BlueWave 200 ultraviolet spot-lamp system from DYMAX comes with an integrated intensity adjustment feature that allows a constant intensity level to be maintained during production. This ensures a fast, low-shrinkage cure of the adhesive, minimizes the heat development and protects sensitive components. Reaching intensities of more than 17 W/cm2, the BlueWave 200 primarily emits UVA and visible light (300–450 nm) to match the curing needs of photo-initiated adhesives. The intensityadjustment feature allows users to take control of the desired intensity level and compensate for any decline due to aging. A removable knob on the front panel gives the user easy access to manually adjust the emitted intensity level. www.dymax.com RGB LED Marktech Optoelectronics Marktech Optoelectronics has announced the availability of the LC503NPP-20H-A3, a 4-lead, RGB solidstate light source from Cotco. Combining high light output, low power consumption and highreliability materials, the LEDs are said to be ideal for colour-changing applications. The emitter comes in a 5 mm package and uses a round water-clear lens. Other specifications include a 20° viewing angle and an operating O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e temperature range of –40 to 95 °C. Incorporating InGaAlP and InGaN technologies, the luminosity is quoted as up to 4180 (red), 4180 (green) and 1100 mcd (blue) at 20 mA. The 4-pin package allows the red, green and blue chips to be controlled individually. www.marktechopto.com Power and energy meters Laser Lines Laser Lines has added the SOLO2 and the UNO to its Gentec EO monitor family. The SOLO2 is a power and energy meter that is ergonomically shaped and can read high repetition-rate energy detectors up to 3 kHz. The firm says that the SOLO2’s screen is twice as large as that of the SOLO-PE. It is also compatible with all Gentec power meters and energy detectors up to 3 kHz. The UNO power meter has the same ergonomics as the SOLO2. The company says that the UNO combines a large screen and easy navigation in an affordable package that includes the most useful functions. www.laserlines.co.uk Specialist UV lenses Resolve Optics Resolve Optics designs optical elements out of synthetically fused silica or ultravioletgrade calcium fluoride to provide the best possible transmission in the ultraviolet (UV) range. Using proprietary UV antireflection multilayer coatings, the firm achieves wide spectral coverage from 230 to 500 nm and offers greater than 99% transmission per surface. As well as custom designs, the company also offers a range of standard high-performance UV lenses including a unique high-performance 60 mm focal-length forensic UV lens for use with reflected UV imaging systems. This lens has a 8.3° field of view at a magnification of 1:1.25, rising to 16.6° at long object distances. www.resolveoptics.com Single-emitter diode laser nLight nLight has released a beta version of its 30% fill-factor conduction-cooled “CS” bar, rated at 60 W. By combining its proprietary facet passivation technology with AuSn solder on an expansion-matched CuW sub-mount, the firm says that it is able to offer a significant increase in brightness over the previous 40 W, while increasing lifetime in both continuous-wave and on/off applications. Specific wavelengths ranging from 790 to 830 nm can be customized for OEM applications. Each device will have 19 × 150 µm emitters on a 500 µm spacing, conforming to industry standards. Typical operating currents are quoted as approximately 60 A, with a compliance voltage of <2 V. The output is TE-polarized and nLight can include an AR-coated cylinder lens to collimate the fast axis. www.nlight.net CCD camera SVS-VISTEK The svs16000 from SVSVISTEK is a progressivescan 16 Mpixel camera with a resolution of 4904 × 3380 pixels. It is based on an interlinetransfer charge-coupled device from Kodak with a diagonal of 43.3 mm. The ultrahigh-speed version has a frame rate of up to 3 full images per second while in partial scan mode images with fewer lines can be read out at a considerably higher speed. SVS-VISTEK’s ConvenientCam configuration software allows users to adjust camera parameters such as gain, offset and exposure time. Variable operation modes such as free running or triggered allow the user to easily integrate the camera into their application. The camera measures 65 × 67 × 45 mm making it ideal for space-sensitive applications. www.svs-vistek.com LEDs Moritex The new line of dome-type LED light sources from Moritex has been designed to evenly illuminate object surfaces for image processing and inspection applications. Two different sizes of MG-Wave dome LEDs are available, each in four different wavelengths: red, green, blue and white. Unlike other forms of lighting, the firm says that repeatedly switching the light on and off doesn’t cause deterioration. A narrow bandwidth is also said to make it easy to acquire the contrast essential for image processing. The MG-Wave range also includes high-powered spot, direct ring, low-angle ring, shadowless, edge backlit, array backlit, coaxial, bar, linear, oblique and parallel lighting LEDs, as well as power sources and a wide variety of LED lighting accessories. www.moritex.com 29 PRODUCTS Integrating sphere Optronic Laboratories The OL 700-4pi integrating sphere from Optronic Laboratories is designed to accurately measure the luminous flux of LEDs. Specifically, Optronic says that the product has been designed in anticipation of the new LED measurement recommendations from the CIE for total luminous flux and partial LED flux measurements. This single and easy-to-use accessory can be used in tandem with the OL 770-LED test and measurement system. The LDX-3600 Series High Current Laser Diode Drivers combine high current output with multiple levels of laser diode protection for safely controlling high power laser diodes. These products are being developed to deliver output current ranging from 10A to 120A with a compliance voltage of up to 30V in CW or QCW mode and designed to deliver the precision, power and flexibility needed for R&D as well as manufacturing test applications. The LDX-3600 Series intuitive front panel is designed for quick and easy operation without confusing multi-level menus. Dual displays allow simultaneous indication of laser current, voltage, or power while at the same time monitoring laser diode temperature. Laser diode current, voltage and temperature limits along with pulse mode parameters such as pulse width and duty cycle are quickly and easily set. A unique power display mode allows laser diode power to be set based on slope efficiency and threshold current parameters. External output power monitoring is supported through an independent photodiode measurement circuit. Developed for automated laser diode testing in CW or pulse mode, these drivers combine an IEEE-488/GPIB interface with trigger inputs and outputs and precision four-wire voltage measurement for fast, accurate, high power laser characterization. In addition, the LDX-3600 Series incorporates multiple levels of laser diode protection including adjustable current and voltage limits, output shorting relays, soft turn-on/off circuits and transient protection during power up and laser operation. A thermistor based temperature monitor provides additional protection through a programmable temperature limit which can be used to shut off the laser output when a temperature limit is exceeded. Dual independent interlocks are provided for further laser and operator protection. To learn more about the new LDX-3600 Series High Current Laser Diode Drivers, visit our website at www.ilxlightwave.com or contact one of our sales engineers at (001) 406-556-2481. 800-459-9459 406-556-2481 www.ilxlightwave.com Celebrating 20 Years of Innovation 30 www.olinet.com UV diode laser systems TOPTICA Photonics German firm TOPTICA Photonics has expanded its range of high-power frequency-doubled all-diode laser-based systems into the ultraviolet (UV). Starting with a wavelength of around 670 nm, the TA-SHG 110 offers output powers of more than 100 mW between 329 and 336 nm. The firm says that the continuous-wave UV emission has a very narrow linewidth, is tunable and spatially singlemode. Industrial applications include interferometry, holography, biophotonics and Raman spectroscopy. Scientists performing spectroscopy, cooling and trapping of atoms, ions and molecules could also benefi t from the laser system. www.toptica.com Interferometer PROMET International The FiBO 300 interferometer from PROMET International offers 3D surface mapping and visualdefect evaluation capability from a portable and vibration-insensitive design. Equipped with calibrated objectives ranging from 1.8 to 20×, possible applications include inspection of multimode 125–700 µm fibre connectors, photonic crystal fibre, microlens arrays and other components less than 1 mm in diameter. The FiBO 300 also comes with Durango software for advanced interferometric measurements and highly specialized applications. With a kinematic snap, the firm insists that the FiBO 300 guarantees exact positioning and eliminates tedious adjustments when switching between fibre types, connector styles and PC/APC polishes. www.promet.net O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e Brilliant EaZy Streamlined EaZy Upholds Superior “Brilliant” Performance PRODUCTS DPSS lasers Cobolt Cobolt of Sweden has released higher-power versions of its continuous-wave Cobolt Calypso lasers while retaining the compact package and optical performance of lower-power models. The single-line Cobolt Calypso is now available with up to 100 mW at 491 nm and the Cobolt Dual Calypso with up to 50 + 50 mW at 491 + 532 nm. All Cobolt lasers are single frequency with very narrow spectral bandwidth (typically <30 MHz). The firm quotes a root mean square noise of <0.3%, peak-to-peak noise of <3%, a beam quality of M2 <1.1 and a power consumption for the full system of <40 W. www.cobolt.se 3CCD remote-head camera Toshiba Imaging Systems Q-Switched Nd : YAG Laser with added EaZe-of-Use • 330mJ in 6ns @1064nm • Detachable Cables • Prompt Set-up and Warm-up Times • Bookshelf Power Supply, 12kg (appx 27 lbs) • Ergonomic Remote Control Box All Brilliant Features: - High Quality Beam Profile - Interchangeable Harmonics Generators - Field Proven Reliability and Stability www.quantel-laser.com www.bigskylaser.com O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e The IK-TU51 highresolution, 3CCD remote-head camera from Toshiba Imaging Systems is available with 1/3 - and 1/2 -inch image sensors. High sensitivity (800-line resolution) plus interchangeable heads combine to make this video camera ideal for a variety of industrial, entertainment and R&D applications. The camera provides real-time imaging with 10-bit digital signal processing. The imager offers a frame memory for continuous video imaging in integration mode, a freezeframe function, and a user-selectable one- or two-pulse triggering mechanism. Additional features include 0.02 lx (at 4 s exposure), a 14-step detail-enhancement capability and a six-vector colour-enhancement circuit. The IKTU51 is available with an RS-232C interface, LVDS digital and RGB analogue outputs, and a standard C-mount lens flange. www.cameras.toshiba.com NIR detector array Andor Technology The iDus InGaAs detector array system from Andor Technology is the latest addition to its iDus range of spectroscopic detectors. Available with a choice of a 512- or 1024-element photodiode array, the product covers the wavelength range between 800 and 2200 nm. Other specifications of the product include a peak quantum efficiency of >80% with low noise, thermo-electric cooling to –85 °C for optimal signal-to-noise performance and simple USB 2.0 connectivity. Coupled to one of Andor’s Shamrock spectrograph models, the Andor iDus InGaAs detector array is ideal for a diverse range of nearinfrared spectroscopy applications. www.andor.com 31 Project11 19/2/07 10:05 Page 1 LASER 2007 World of PHOTONICS 18 t h I NTE R NAT I O NAL TR AD E FAI R AN D CONGRESS FOR OPTICAL TECHNOLOGIES— COMPONENTS, SYSTEMS AND APPLICATIONS LIGHT AT WORK A LEADING INTERNATIONAL TRADE FAIR DOES NOT ORIENT ITSELF TO STANDARDS. IT IS THE STANDARD. No other exhibition presents innovative optical technologies in direct combination with industrial application sectors for various branches of industry— as “light at work.” That makes LASER. World of Photonics the most important business and networking platform for all market leaders, decision-makers and users—just like you. Take advantage of the benefits of online registration now at www.world-of-photonics.net NEW MUNICH TRADE FAIR CENTRE 18–21 JUNE 2007 www.world-of-photonics.net PRODUCTS Power combiner SIFAM Fibre Optics Suitable for use in the latest generation of fibre lasers and high-power fibre amplifiers, SIFAM has introduced a range of state-of-the-art highpower combiners that can combine the power of up to 19 fibre-coupled laser diodes into a single output fibre. SIFAM says that its customers have used these components to achieve combined optical output powers of over 100 W continuous-wave and 100’s kW pulsed. High-power combiners are available in 6 + 1 × 1 configurations with singlemode and polarizationmaintaining feed-throughs. Combiners with large mode-area central-fibre feed-throughs are also available giving improved optical brightness. Using the same technology platform, 1 + 1 × 1 configuration solutions are also available for low power applications such as printing. www.sifamfo.com Optical glass AFO Research AFO Research has completed testing of its next generation of speciality optical glasses for the communications, medical-laser and commerciallaser industries. The firm says that its glasses have superior optical characteristics compared with commercially available products such as BK20, ZBLAN, Phosphate and FP 20. According to the company, its AFO glasses will form the core of better-performing highpower compact lasers, high-power fibre lasers and high-power fibre amplifiers. “By offering a lower-cost, high-quality glass to optical-device and component manufacturers, the resulting improvements in performance at lower cost can drive profitability better than any glass currently on the market,” said Jack Illare, chairman and president of AFO Research. www.aforesearch.com Direct-drive rotary stages Aerotech Aerotech’s ALAR large-aperture rotary stages combine brushless direct-drive motor technology and integral precision encoders with angular contact bearings for backlash-free, fast and ultraprecise positioning with a high payload capacity. Featuring compact space-saving housings with aperture sizes of 100, 150, 200, 250 and 325 mm, the range is aimed at high-throughput single- and multi-axis testing, and alignment applications across manufacturing and research. O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e Accuracy across the range is listed as 3.9 arcsec (calibrated) and repeatability is 0.3 arcsec. The fundamental stage resolution before encoder multiplication is between 4.3 and 10.3 arcsec. With Aerotech controls, the resolution is increased to between 1000 and 8000× making the useable stage resolution as low as 0.00054 arcsec. The range is available in continuously rotating or limited travel versions and each aperture size is offered in two height configurations. Order Today Get it Tomorrow www.aerotech.co.uk CCD camera Prosilica Prosilica is now shipping its GE2040 gigabit Ethernet camera in response to customer demand for a compact, high-resolution machine-vision camera with fast frame rates and excellent sensitivity. The device incorporates Kodak’s state-of-the-art KAI4021 progressive-scan charge-coupled device sensor and delivers 2048 × 2048 resolution at 15 frames per second. Both monochrome and colour versions are available with either C-mount or F-mount fixtures. The camera housing measures approximately 4 × 5 × 6.5 cm and, like all of the firm’s cameras, includes an electronic shutter for capturing highspeed motion events. Fitted with direct RGB24 output, the camera is said to suit a wide range of applications such as flat-panel display and PCB inspection, medical imaging and general machine vision. Prosilica says that the GE2040 is particularly suited to traffic- and publicsecurity applications thanks to the camera’s high resolution and snapshot shutter. www.prosilica.com Fibre laser NP Photonics NP Photonics has introduced the Rock, a single-frequency fibre laser that is insensitive to vibration and does not require active stabilization. The Rock is based on a passive stabilization technique developed by the firm for DWDM fibre-optic sensing systems. This method is said to significantly reduce the sensitivity of the frequency noise to vibration and low-frequency acoustics. According to Philippe Brak of NP Photonics, the Rock, which is now ready for production, will reduce the cost and complexity of actively stabilized multilaser systems by 50%. Brak explained that this breakthrough is important because multilaser systems are expected to double the productivity of oil fields and significantly increase the security of harbours. www.npphotonics.com 80% of All Orders From Europe Reach Your Lab the Next Day • Over 10.000 Photonics Products • Check Availability on Our Website • Order Online or at Any European Office • Free of Extra Charge Now Same Day Shipping Also From Europe Why Wait Longer . . . ? www.thorlabs.com Request Your FREE Tools of the Trade Catalog With Over 10,000 Products. Order Online at www.thorlabs.com Over 700 New Products! PRODUCTS 3D-surface metrology systems Zygo Control software JPSA Zygo has released a new addition to its NewView line of high-performance 3D-surface metrology systems. Focusing on affordability and simplified operation, the NewView 600 series comes in a compact package designed to meet the needs of research and production. According to the firm, the NewView 600 is ideally suited to fast, non-contact, 3D-surface topography measurement and offers high precision, simplified operation, configuration flexibility and advanced data analysis. The product is available as a complete stand-alone system or as an integrated metrology module for OEM applications. JPSA, a designer of ultraviolet laser materials processing workstations, has come up with comprehensive system-control software. The JPSAControls32 package offers features such as a system configuration editor for manipulating software settings and a CAD file translation capability to automate the programming of complex designs. The software allows the set up and control of motion elements, including linear stages, rotary stages and motorized beamdelivery system components, as well as laserfiring mechanisms. Other benefits of the package include a high-level programming language and a wafer-scribing macro builder. www.zygo.com NIR diode lasers DILAS Diode Laser DILAS has released near-infrared diodelaser sources emitting 60 W continuous-wave from a single 19-emitter bar at 808 and 980 nm. Available in a 25 × 25 mm conduction-cooled package, these multimode diode lasers are said to be the ideal pump source for solid-state lasers used in medical and industrial applications. The devices have an operating current of 60 A and a compliance voltage of 1.7 V. Beam divergence is specified as <65° × <10° for 90% enclosed power. The firm adds that it can include an AR-coated aspherical cylinder lens to collimate the fast axis to <12 mrad. For applications requiring a collimated beam, the company’s slow-axis lensing capability can further improve bar brightness. www.jpsalaser.com CCD camera JAI JAI has introduced a series of 4 Mpixel (2048 × 2048) cameras that can be softwareswitched between dual-tap mode operating at 15 frames per second (with automatic channel balancing) and single-tap mode operating at 8 frames per second. The series is based on Kodak’s high-fidelity 1.2-inch progressive-scan IT charge-coupled device sensor (KAI-4021) and includes both monochrome and Bayer CFA colour models. Units are available with a choice of Camera Link or GigE Vision gigabit Ethernet digital interfaces. All devices feature image-centre partial scanning (100, 250 or 500 lines) as well as variable partial www.dilas-inc.com scanning where the user can choose both the starting point and the specific number of lines to be Laser-machining system Process Photonics scanned. Full-frame shuttering of up to 1/16000 s, asynchronous reset and no-delay pulse-width Process Photonics, US, control shuttering are also included. has launched a laserOther features include a 2X binning mode, machining system that is capable of high-speed selectable in the horizontal direction, vertical processing of rigid board direction, or both; a PIV mode enabling the capture of pairs of images separated by only a few and flex materials, as microseconds; and defective pixel compensation. well as green ceramic tape. Dubbed FP1000, www.jai.com the workstation features active pulse shaping for superior process quality IR camera module MultiPix and high-performance motion and laser-beam control for rapid, accurate panel processing. Jenoptik’s IR-TCM 640 high-resolution infrared The unit is equipped with a Windows-based (IR) camera module is now available from MultiPix operator interface and programmable processes Imaging. According to the firm, this is the first include via-drilling, skiving, cutting and routing. commercially available camera module offering According to the firm, the entire FP series of VGA resolution (640 × 480 pixels) in real time. products is designed to suit industry-standard file When configured with an optional hardware formats and data-logging requirements. Software extension for resolution enhancement, the allows the machine to adapt to small-lot, high-mix camera can produce photo-realistic IR pictures and high-volume production requirements. with 1.2 Mpixel resolution. Based on an uncooled microbolometer, the IR-TCM 640 is said to suit www.processphotonics.com 34 O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e High-Power NanoScan for High Power Lasers NIST-Traceable ♦ Measure focused CO2 laser ♦ ♦ ♦ ♦ beams up to 5kW Determine beam size and position simultaneously Unparalleled accuracy, speed and ease-of-use Wavelength range from 190nm – >100µm Beam sizes from 20µm to ~17mm ♦ CW and kHz pulsed beams ♦ Q-Switch ♦ PWM ♦ Even femtosecond lasers! visit www.photon-inc.com to find your nearest Photon representative PRODUCTS machine-vision and security applications, and is equipped with standard Firewire, S/C Video and RS232 interfaces. www.multipix.com Optical Power Meters Vibration and topography measurement Polytec Polytec is now offering a measurement-services programme that it claims makes advanced non-contact vibration and topography measurements available for every budget. By eliminating the need for a capital purchase and/or the addition of dedicated manpower, the firm believes that its package suits engineers who have short-notice critical needs. The equipment on offer includes 1D and 3D scanning-laser vibrometers, single-point vibrometers, microstructure (MEMS) motion analysers and topography measurement systems operated by experienced application engineers. The technology is fundamentally non-destructive, works on most surface finishes, eliminates mass-loading and minimizes contact transducer mounting, wiring and signal conditioning. Tests may be run at the customer’s facility or in one of three of Polytec’s North American laboratories in Detroit, Los Angeles and Boston. Data can be exported in several formats for further processing, such as FE correlation and modal analysis. www.polytec.com Thin-film coatings DSI Deposition Sciences Inc (DSI) has released a dichroic hybrid coating that is designed to be highly reflective over selected wavelength bands and minimally reflective over the rest of the spectrum. According to the firm, its HeatBuster Spectral Metal thin-film-coating line combines the spectral advantages of glass mirrors with the cost savings and durability of sheet-metal fabrication. The base material for the new product is highly polished stainless steel. A dark mirror coating is initially deposited onto the substrate to optically couple the unwanted wavelengths into the metal. Finally, a highly reflective dichroic coating is then applied to the dark mirror to provide spectral selectivity. For curved optics, the parts can be formed using standard sheet-metal fabrication methods prior to coating. Curved collection optics can be fabricated as long trough reflectors and then laser-cut into segments of the desired length. Alternatively, the HeatBuster Spectral Metal sheets can be laser-cut into simple or complex shapes after the coating process. www.depsci.com O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e Complete Family for Power Range 5nW to 30W • High Power & High Sensitivity Power Meters • Analog & Digital Displays • Interchangeable Sensor Heads • Photodiode & Thermal Sensors • Slim & Integrating Sphere Sensors • NIST-Traceable Calibration Hungry for your thoughts . . . Share your product ideas. www.thorlabs.com Request Your FREE Tools of the Trade Catalog With Over 10,000 Products. Order Online at www.thorlabs.com Over 700 New Products! PRODUCTS market-driven understanding of technology TRISTAN® The World’s most innovative Spectrometers LED flash driver NXP NXP, a semiconductor company founded by Philips, has unveiled its portfolio of solidstate lighting electronics. The UBA3001 is a camera-phone LED flash driver that produces the maximum flash-light output at the highest efficiency from a battery-operated mobile handset, says NXP. The unit offers a programmable output current of up to 1000 mA in flash mode, up to 850 mA in flash-during-transmit mode, up to 300 mA in torch mode and up to 5 mA in indicator mode. Other application areas for the firm’s technology include automotive and general lighting. laser beam diagnostics Beamlux II software • Evaluation compliant to ISO • multiple camera support • high measuring rate • automation of measurements • for R & D and production www.nxp.com Alignment laser Photonic Products New Features • Truly mobile spectroscopy solutions • WLAN & Bluetooth interfaces • 2048 x 14 px back-thinned detector •Touch-screen & integrated OS Pre-configured Versions: Photonic Products has launched a 645 nm laser-alignment module that it says is ideal for use in industrial alignment and machine vision. The 300-0100-00 series comes with a range of interchangeable pre-aligned precision optics including an 88° cross, 58° line and a 58° cross/spot. Both the laser intensity and focus can be adjusted by the user with the intensity ranging from 0.1 to 4.5 mW. With a diameter of 14 mm, the laser-diode module incorporates anti-surge, anti-static and reverse-polarity protected electronics; an anti-reflection coated scratchresistant glass window to protect the internal optics; and a 2.1 mm jack socket. www.photonic-products.com Customized spectral range available! Order your catalog now: catalog@mut-gmbh.de m·u·t GmbH fon: +49 (0)4103 9308-0 info@mut-gmbh.de m·u·t America, Inc fon: +1 (804) 512-3449 info@mut-america.com m·u·t Asia Ltd fon: +86 (21) 639 19 319 ext. 19 info@mut-asia.cn www.mut-gmbh.de 36 Ultrafast oscillator Newport The Mai Tai DeepSee from Newport is ideal for basic research and biological imaging applications such as multiphoton microscopy. Complete with automated group velocity dispersion compensation, the new Mai Tai delivers more than 300 nm in useable tuning range and more than 2.5 W of average power. “In order to provide users with a hands-free, out-of-the-box solution, we are very excited to introduce the Mai Tai DeepSee,” said Philip Smith, product manager for Newport’s SpectraPhysics Laser Division. “This new laser is an ideal solution that incorporates automated dispersion compensation and enables biologists to image deeper while preserving the integrity of their living tissue sample.” www.newport.com Beamprofiler cameras • industry standard • USB, Fire Wire, Analog • XUV...VUV...VIS...IR • high resolution • high dynamic customized solutions Optische Messtechnik GmbH fon: +49 (0) 5 51 7 97 67 -0 info@metrolux.de www.metrolux.de Beamlux II demo software available O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e PRODUCTS Fibre-bundle laser Lumics generation, fluorescence upconversion and the investigation of non-linear optics. Lumics is now producing a laser that emits up to 300 W of optical output power at a wavelength of 900 nm from a multiple fibre bundle with a single-connector output. The LU0975C300 uses a standard SMA 905 output connector that is specified with a 1 mm fibre diameter. The laser diodes are assembled on a watercooled plate in a space-saving double-layer design. Available at 915, 940, 960 and 975 nm, the product uses very small TO220 fibre-coupled single-emitter diodes and operates over an ambient temperature range of 0–50 °C. The footprint is specified as 310 × 170 mm with a maximum height of 70 mm. The laser suits industrial laser applications as a pump source or direct-diode applications in material processing. www.lumics.com Ti:sapphire ultrafast amplifier Coherent Coherent has updated its Legend series of Ti: sapphire regenerative ultrafast ampliers. The Legend Elite features the same form dimensions and integrated-software interface as earlier models, which simplifies upgrades for end users and system builders alike. The unit is available with several different pulse-width options, ranging from femtosecond through to picosecond output. Major improvements include superior stability and the ability to generate extremely short (< 35 fs) pulses. According to the firm, the one-box amplifier can be operated as a turnkey tool for many hours of continuous operation without the need for external adjustment. Applications include the study of molecular dynamics, photochemistry, photoelectron www.coherent.com Objective focusing system piezosystem jena Piezosystem jena says that it has developed its latest micro-objective focusing system – the MIPOS 500 UD – especially for applications requiring upside-down operation, such as inverted microscopes. The company says that the design is free of mechanical play, provides a total travel of 500 µm and a resolution in the nanometre range. As with other members of the MIPOS series, mounting the 500 UD is simple. It involves screwing a FLEX-Adapter thread-ring into the imaging system (for example, a microscope) and mounting the MIPOS 500 UD onto this ring with a clamping screw. Integrated position sensors also guarantee positioning without hysteresis and drift. The MIPOS 500 UD is being targeted at applications in biology, laser technology and medicine where highresolution precision positioning is critical. www.piezojena.com Optical sensor interrogator Micron Optics Micron Optics is offering a high-speed optical sensing interrogator for monitoring and analysing vibration modes on up to four channels simultaneously. The si920 can operate with acquisition rates as fast as 500 kHz on a single channel or 100 kHz on four-parallel channels. Featuring Fabry-Perot tunable filters, the unit is designed for use with fibre-Bragg grating sensors that can be deployed in applications such as ballistics testing, blast analysis and acousticemissions monitoring. www.cvilaser.com OBC ELCAN Optical Technologies www.ELCAN.com 13 Fujifilm Recording Media www.polymer-optics.com www.gentec-eo.com 6 www.oerlikon.com/optics 9 26 www.globallasertech.com 14 30 www.instrumentsystems.de 27 28 Ophir Optronics www.ophiropt.com OSRAM www.osram-os.com/GLDS Pacer International www.pacer.co.uk PCO www.pco.de Photon Inc www.photon-inc.com Quantel www.quantel-laser.com Scitec Instruments www.world-of-photonics.net 32 Stockeryale Inc 19 34 36 4 Texas Instruments ILX Lightwave www.ilxlightwave.com Instrument Systems IPHOBAC www.ist-iphobac.org Laser 2007 Exhibition Laser Components (UK) Ltd www.lasercomponents.co.uk Lee Laser www.leelaser.com M.U.T. www.mut-gmbh.de Melles Griot www.mellesgriot.com 36 22 www.newport.com Ocean Optics www.oceanoptics.eu Oerlikon Optics Global Laser Technologies 8 IFC, 15 IBC 12 31 35 31 www.scitec.uk.com • Stepper Motor Controller • Piezo Controller • Shutter Controller • Strain Gauge Reader • USB Hub for up to Six Controllers www.stockeryale.com www.dmddiscovery.com Thorlabs www.thorlabs.com Topa Verpakking www.topa.nl Share your product ideas. www.thorlabs.com Request Your FREE Tools of the Trade Catalog With Over 10,000 Products. 18 28 7 33, 35, 37 18 The index is provided as a service and, while every effort is made to ensure its accuracy, Optics & Laser Europe accepts no liability for error. O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e • DC Servo Controller Hungry for your thoughts . . . Metrolux Optische www.metrolux.de New Focus www.newfocus.com Newport Spectra-Physics 9 Gentec Electro-Optics Small Form Factor T-Cube Drivers www.micronoptics.com ADV E R T I S E R S’ I N D E X CVI Technical Optics Motion Control Drivers Order Online at www.thorlabs.com Over 700 New Products! BAC K C HAT CEO shares secrets to running a successful high-tech start-up What are the key attributes that make a successful business leader? In this month’s interview Per Ibsen, CEO of Kaleido Technology, offers his thoughts on what it takes to manage a technology company. What personal qualities do you need to lead a technology business? Persistency and motivation are essential. It is very important to be able to motivate not only your employees, but also the board and venture capitalists. You have to remain enthusiastic even when the firm hits stumbling block after stumbling block. It can take a lot of research to get the business up and running and this can involve spending long periods of time in uncharted territory. In fact, when you are putting together a business plan, you can be sure that there will be surprises along the way. You try to take everything into consideration at the start, but there will always be things that come up and make it harder for the company to reach its goals. When we started Kaleido, we were confident that we could purchase equipment that would help us leap towards our goal of producing moulded integrated optics. It turned out that when we bought the equipment and squeezed the machines as hard as we could, they just didn’t live up to our expectations. The state of the art was much lower than we had perceived, which came as a surprise as I have built million-Euro clean rooms where usually 85–95% of the equipment is functioning to specification. I would say that it’s a good idea to multiply the time schedule for reaching your goals by two, three or even pi, as some people suggest. You should be very flexible and fast to adapt to changes once you are on the move. It is important to communicate to shareholders and other interested parties where the company is now and what its future looks like. 38 Kaleido Technolog y Per Ibsen is well versed in taking technology into the marketplace. Back in 1991, he founded Danish fi rm Ibsen Microstructures to focus on the industrial application of diffractive optics. The company was sold to ADC Telecommunications in 2000 for $80 m (760 m) and then became Ibsen Photonics following a management buyout one year later. Today, Ibsen is putting his management skills into practice as CEO of Kaleido Technology – a start-up specializing in freeform and integrated optics. Knowledge is power: Per Ibsen believes that the CEO must be able to get to grips with the technology. What do you think is the best way to to focus on the business. This is the case in prepare for the role? the US where the figure is probably closer to Good business-development skills are important and you must understand the technology. Some people say that a CEO can have a solely commercial background, but in this case you would need to be very fast in getting to grips with the technology. A product manager who has developed a product from its infancy through to a mature level, touching on all of the different areas and functions, including finding strategic partners and negotiating business agreements, would be an ideal candidate. I took a different path. Following my MSc, I was employed for just one year in a company making embossed holograms for credit cards. When the fi rm went bankrupt, I had the opportunity to buy all of the equipment and to continue. It was a hard way to learn and I can see now that with the background of a product manager the fi rm’s development time could have been cut by several years. How can starting up a company be made easier? 715 m for the fi rst funding round. You should try and enhance the group of people around the company as a way of bringing in additional experience. At the beginning, the skills of the start-up are limited, so you should try to close the holes. You can do this through consultants or by putting together an advisory board that contains technologists as well as investment managers. Company founders should admit that they need help and get professional advice. What is your dream for Kaleido? I want to integrate optics, prisms, lenses and everything in one monolithic unit. If you look at electronics, it was only when components became integrated that applications started to take off, and this is what we want to achieve with Kaleido. Using wafer-moulding techniques, our dream is to offer a rugged design with many functions in one simple plate. Today, we make machined components with freeform surfaces, but the final plan is to provide wafer-moulded optics. We have been talking with a lot of Asian market leaders and they are very interested in the technology. Right now our next step is to find a strategic partner. Q In Denmark, when a company is at seed level then you are typically working with fi rst-round funding of around 72 m. The trend is to go through many “pipette” financing rounds. In my opinion, it would be better to take a lot more money in the For more information contact pei@kaleidofi rst round and have the peace and quiet technology.com. O L E • M a r c h 2 0 07 • o p t i c s . o r g /o l e Project3 23/2/07 11:49 Page 1 www.osram-os.com/GLDS G.L.D.S. Global Laser Diodes Specialists Meet the G.L.D.S. team from OSRAM Opto Semiconductors, your No. 1 partner for all laser diode solutions. Worldwide. Equipped with a full line of state-of-the-art laser bars and our new laser stacks, the G.L.D.S. team delivers the right product and the laser expertise. Brilliant minds, brilliant innovation, brilliant ideas – the outstanding assets of the G.L.D.S. Your experts in laser technology. 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