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    • Volume 37, Issue 5

    More content from Volume 37, Issue 5

    Modern trends in fields such as conformal optics, optical testing, and optical lithography have compelled optical designers to take a fresh look at how an optical surface is defined...
    May 1, 2001
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    Stellar interferometry is rapidly evolving from a laboratory experiment to a mainstream observational technique used by astronomers to image stellar surfaces, multiple-star systems...
    May 1, 2001
    Coherent Inc. to acquire DEOS; Scientech wins Laser Megajoule contract for calorimeters; Sharp to build a semiconductor laser-diode plant...
    May 1, 2001
    eMagin wins $5 million to develop bright microdisplay; Cognex and ESI plunge into patent dispute; Kodak forms global imaging business...
    May 1, 2001
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    As photolithography tool manufacturers hone in on 157-nm wavelengths, they will also need to optimize purge-flow systems and material chemistry to prevent lens contamination caused...
    May 1, 2001
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    Strange crystals studied using atomic force microscopy (ATM) have been found by researchers to change shape upon exposure to ultraviolet (UV) light.
    May 1, 2001
    FIGURE 1. Adaptive interferometer based on the polarization self-modulation effect achieved the fastest response time recorded. An external ac electric field of 3.9 kV-cm-1 was applied to the GaP crystal. The plate's vibration frequency is 27 kHz.
    Measurement of small out-of-plane vibrations of optically rough surfaces is useful in nondestructive testing and condition monitoring. Whereas utilization of polarization self...
    May 1, 2001
    (Photo courtesy of University of Illinois)
    University of Illinois scientist Xinzhao Chu adjusts one of the solid-state lasers comprising the Fe Boltzmann temperature lidar while in flight aboard a research airplane owned by the US National Science Foundation and operated by the National Center for Atmospheric Research.
    A sensitive laser-radar (lidar) system that was first deployed over Okinawa, Japan to observe meteor trails during the 1998 Leonid meteor shower is now being used by University...
    May 1, 2001
    Superlattice quantum-cascade lasers get more power; Stoichiometric LiNbO3 and LiTaO3 show better nonlinear performance; Solid-state Raman amplifier optically induces pulse delay...
    May 1, 2001
    ICO presents Galileo Galileo award; Researchers develop new glass for holographic data storage; MetaStable Instruments receives an SBIR contract to develop laser-beam steerers...
    May 1, 2001
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    On Aug. 1, 2000, within days of a picture-perfect launch on July 19, the Fourier Transform Hyperspectral sensor aboard the US Air Force MightySat II.1 sent back its first "hypercube...
    May 1, 2001
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    Even in light of the recent upheaval in the telecommunications market, the world of optical networking continues to face a major challenge—namely, the increasing demand ...
    May 1, 2001
    Over the past decade, cavity ringdown spectroscopy has emerged as a powerful technique for performing direct absorption measurements using pulsed lasers. Developed in 1988, cavity...
    May 1, 2001
    Glass microspherical resonators are precision submillimeter-sized beads that support optical whispering-gallery modes, which are light paths that skip along the surface at grazing...
    May 1, 2001
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    The sequencing of the human genome is the biggest watershed event in science since the lunar landing. But the potential value of this exciting news has an even bigger impact.
    May 1, 2001
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    Ultraviolet applications are increasingly demanding, requiring higher damage resistance on substrates, polishes, and coatings.
    May 1, 2001
    FIGURE 2. Multiple experimental configurations can be established using a single 32-anode PMT. In configuration 1 (top), the light intensity at many widely separated locations is measured simultaneously. In configuration 2 (center), the spectral lineshape can be recorded simultaneously in a manner similar to that of a CCD camera, and in configuration 3 (bottom), the temporal response at several different wavelengths can be measured simultaneously.
    Equivalent to having multiple photomultiplier tubes located in a single housing, the multiple-anode PMT can detect both the temporal and spatial distribution of signal intensity...
    May 1, 2001
    (Photo courtesy of Melles Griot)
    FIGURE 1. Assortment of post-mounted commercial lens holders includes, from left to right, a fixed lens holder using a retaining ring, a translating lens holder, an adjustable lens holder, and a self-centering lens holder.
    Choosing the optimum mount for an application requires an understanding of the basics of optical alignment and mount performance.
    May 1, 2001
    FIGURE 1. When short, intense pump pulses are used for optical parametric generation, a single pass through an NLO crystal is enough to convert a substantial fraction (>10%) of the pump energy into the signal and the idler (a). For pump pulses with smaller intensity, parametric frequency conversion is weaker and a resonator OPO cavity is used (b). For narrow-linewidth OPO applications, a diffraction grating can be incorporated into the cavity (c). When tight focusing is required with a CW pump, a four-mirror ring OPO cavity with two flat and two concave mirrors can be used (d).
    New nonlinear materials extend the tuning range of optical parametric conversion techniques beyond 5 µm and open up new applications in molecular spectroscopy.
    May 1, 2001
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    Electroholography is an inherently different switching technology that permits true all-optical switching at high rates in a compact package.
    May 1, 2001
    A large spherical composite mirror array was made for a high-energy physics experiment in Hamburg, Germany. The total collecting area of the array is 5 m2, while the areal density...
    May 1, 2001
    (Photo courtesy of Lasertec USA)
    FIGURE 1. Confocal image contains a measurement of a 0.273-µm photoresist line on a silicon wafer taken at a 5600X magnification, equivalent to the resolution of a scanning electron microscope. The profile overlay is taken along the horizontal solid line. The width is measured at a 50% slice level, meaning that the measurement is made at the halfway point between the bottom and top of the resist line. This slice level can be adjusted between 5% and 95%, so the width can be measured at any elevation on the side wall that is required. The height of the photoresist line is 0.29 µm. The height, as well as the width, can be rapidly measured to a precision of 0.001 µm. The repeatability of measurement in the horizontal and vertical direction is 0.02 µm.
    Used as the light source for a confocal laser scanning microscope, a 410-nm-emitting diode laser boosts image resolution to that of a scanning electron microscope.
    May 1, 2001
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    So you want to be an entrepreneur, but you're just not sure. And you wonder: Should I quit my well-paid job in the middle of a recession, raise money on 37 credit cards, build...
    May 1, 2001
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    As the global optical networking infrastructure evolves into the de facto foundation for the convergence of datacom and telecom applications, the need for highly reliable and ...
    May 1, 2001
    Hollow-core photonic bandgap fibers guide only certain wavelengths, depending on their design. These fibers are illuminated with white light.
    Internal microstructures added to glass fiber create new fibers with properties quite different from those of conventional fibers, such as the ability to guide light through hollow...
    May 1, 2001
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    Since its launch in 1973, the biennial trade fair has become one of the world's largest events devoted to laser technology and optoelectronics.
    May 1, 2001
    Accessories for fixed-stage microscopes; Sampling accessories for NIR analyzer; 4.5-W diode-pumped industrial UV laser; High-speed embedded vision processor...
    May 1, 2001
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    Photomultiplier tube from Hamamatsu Corp., Bridgewater, NJ; Polygon assembly from Lincoln Laser, Phoenix, AZ; PIN photodiodes from Advanced Photonix, Camarillo, CA; Custom optical...
    May 1, 2001
    1304qa Chang New
    I don't play the stock market, but can share a few good ideas I've picked up over the years. Peter Lynch wrote once that at any given time, a stock is at a fair price. The assumption...
    May 1, 2001
    Even in the face of pervasive uncertainty regarding the economic outlook for 2001, the optoelectronics industry has been the driving force behind two blockbuster conferences so...
    May 1, 2001
    I often get requests for advice on writing, particularly from scientists and engineers who feel that writing is difficult. Yes, writing is hard work, but it is not a black art...
    May 1, 2001
    FIGURE 1. Because of their tiny size (edge-emitters usually measure about 100 µm thick by 200 to 300 µm wide by 400 to 600 µm long and VCSELs tend to measure about 300 to 400 µm square), the bonder must be equipped with special viewing capabilities, such as this cube beamsplitter and scope, to allow the operator to first see the device and then, among other things, simultaneously view the diode laser image and the site on the submount where the die is to be placed.
    Packaging optoelectronic components for the telecommunications industry is getting more complicated as vertical-cavity surface-emitting lasers (VCSELs) move from R&D into mainstream...
    May 1, 2001
    FIGURE 1. The transverse intensity beam profile for 0.3 mm spot size (top) and a 1.5 mm spot size (bottom) after VariSpot, as measured with a Photon Inc. (San Jose, CA) video laser beam profiler. False color (red to blue) indicates different (decreasing) local intensity. The incident beam is from a 2 mW HeNe laser.
    Variable spot sizes are nothing new. But a family of zooming optical systems developed by a visiting scholar at Stanford University offers a dramatic improvement in the ability...
    May 1, 2001
    Aeroflex acquires TriLink Communications; CiDRA and Three Rivers Community College kick off training program; Anadigics acquires Telcom Devices Corp....
    May 1, 2001
    NAGOYA—Researchers at the Nagoya Institute of Technology have developed a structural color-forming system that exhibits chameleonlike change of color when influenced by ...
    May 1, 2001
    SAITAMA—Engineers at Sumita Optical Glass have developed an ultraviolet (UV) sensor that maintains constant characteristics over long periods of time (see figure). Ultraviolet...
    May 1, 2001
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    TSUKUBA CITY—Researchers at the Institute of Information Sciences and Electronics at the University of Tsukuba have developed an identification system that uses neural networks...
    May 1, 2001
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    Current light-emitting diodes (LEDs) are based on gallium arsenide and are incompatible with silicon-based circuits, which has created a bottleneck for further circuit-miniaturization...
    May 1, 2001
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    America's prospects for future economic growth hinge on the private sector's ability to innovate and the federal government is encouraged by a new report from the Council on Competitive...
    May 1, 2001
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    Researchers in the department of biology at the University of York (York, England) have used a combination of new imaging technology and optical tweezers to study muscle contraction...
    May 1, 2001
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    Novalux (Sunnyvale, CA) chose the Optical Fiber Communication conference (OFC; Anaheim, CA) in March as the forum to reveal the long-awaited technical description of its "platform...
    May 1, 2001
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    Driving at night on lightly used roads and having to face the headlights of an oncoming car provokes different reactions in different people. Out of fear of annoying the other...
    May 1, 2001
    Under nanosecond laser pulsing, an asymmetrical rotaxane molecule based on hydrogen bonding has demonstrated linear motion similar to that of a simple piston. At room temperature in acetonitrile, a macrocyclic bead-like structure locked onto linear thread in the molecule is induced to shuttle to a second location, in a process that takes about 1 µs (similar to the power stroke of a piston). If necessary, after a charge-recombination process lasting roughly 100 µs, the macrocycle can then shuttle back to its original.
    Although researchers have known about the existence of catenane and rotaxane molecules for a couple of decades, it wasn't until the early 1990s that they were first considered...
    May 1, 2001
    A new way of recording three-dimensional (3-D) information—called spatiotemporal digital holography—should give researchers the option of recording data first and deciding exactly...
    May 1, 2001
    Experimental setup for TPF and SHG imaging can operate simultaneously in transmission and reflection modes. Applications that may benefit include the imaging of biological specimens such as DNA and chromosomes.
    Scientists typically use the various three-dimensional optical-imaging techniques independently when taking measurements. Even an experiment involving more than one two-photon...
    May 1, 2001
    The overarching theme at the Optical Fiber Communication Conference (OFC) in Anaheim, CA, in March was clearly "high volume" - of attendance at the show and of the manufacturing...
    May 1, 2001
    Argon-ion laser and spectrometer are mated to a fundus camera to measure carotenoid levels in the living human macula via Raman scattering (top). Results on a volunteer show two Raman-scattering peaks (bottom). Comparing these peaks to the height of a carbon peak pins down the subject's macular carotenoid concentration at about 400 nm, a typical value for a human subject.
    Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly in the United States. Even when not causing complete blindness, the degeneration produces...
    May 1, 2001
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    Researchers at the University of Michigan (Ann Arbor, MI) are combining Raman microspectroscopy with mechanical testing to gain insight into how chemical variations in bones influence...
    May 1, 2001
    FIGURE 1. All-solid-state UV laser is used to machine the ball-grid array substrates that are being examined by this technician. The Inazuma Nd:YVO4 laser is specified to produce 8 W at 355 nm in a TEM00 beam with M2 < 1.3.
    Engineers at Spectra-Physics Lasers (Mountain View, CA) have demonstrated more than 10 W of Q-switched, ultraviolet (UV) output from a diode-pumped laser, setting a new record...
    May 1, 2001
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    The Optical Society of America's annual Advanced Solid-State Lasers (ASSL) topical meeting provides an intimate setting for world leaders of the solid-state laser community to...
    May 1, 2001