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  • Volume 45, Issue 7

    • Volume 45, Issue 7

    Optics

    Seeing stars and beyond

    Stephen G. Anderson
    July 1, 2009
    Did you know that 2009 is modern astronomy’s quadricentennial?
    Th Manu 01
    Optics

    Manufacturers’ Product Showcase

    July 1, 2009
    G-S PLASTIC OPTICS specializes in the custom manufacture of precision polymer optics for use in imaging, scanning, detection, and illumination applications worldwide.
    Th New P 01
    Positioning, Support & Accessories

    New products

    July 1, 2009
    The SpiceLED series contains devices able to withstand operating temperatures of up to 110°C.
    Lasers & Sources

    Cheaper materials are key to lower-cost solar cells

    July 1, 2009
    A study from the Energy and Resources Group and the Department of Chemistry at the University of California, Berkeley, and the Lawrence Berkeley National Laboratory (Berkeley,...
    Research

    Seen any good ‘captchas’ lately?

    Jeffrey Bairstow
    July 1, 2009
    Despite the early successes of captchas, many academic researchers are itching to crack the technologies they use.

    More content from Volume 45, Issue 7

    (Courtesy of MicroLight)
    FIGURE 1. The ML830 from MicroLight uses three 830 nm laser diodes to penetrate skin to a depth of about 2 in. A red LED guides the collimated output from the laser diodes; the beams diverge slightly as they are absorbed and/or pass through different tissue layers.
    Research

    PHOTONICS APPLIED: PHOTONICS IN MEDICINE: Low-level light therapy: It’s all about wavelength and power

    Gail Overton
    July 1, 2009
    While the benefits and detriments of sunlight have been known for decades, researchers are showing that electromagnetic radiation can be the key to safe and effective medical ...
    (Courtesy of InfraScan)
    The Infrascanner system consists of a Windows Mobile PDA connected by a wireless Bluetooth link to a handheld sensor with disposable fiber optics cap.
    Detectors & Imaging

    MEDICAL SENSING: Inexpensive handheld tool detects brain injuries in the field

    Barbara Gefvert
    July 1, 2009
    About two million Americans suffer concussions each year, and too often the result is severe neurological damage or death.
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    Optics

    A better CGH algorithm creates many focused spots

    July 1, 2009
    Phase-only computer-generated holograms generated by spatial light modulators (SLMs) can be used to diffract an incoming coherent beam into numerous focused spots distributed ...
    Optics

    NANOLITHOGRAPHY: RAPID lithography achieves λ/20 resolution

    Gail Overton
    July 1, 2009
    Because diffraction limits the resolution of conventional photolithography to roughly one-quarter of the wavelength of light used, alternate techniques such as nanoimprint lithography...
    (Courtesy of the University of Cincinnati)
    Cross-section (left) and top views (right) of the display pixels are shown with no voltage applied (upper), confining the pigment to the cylindrical reservoir, and with an applied voltage (lower) that causes the pigment to disperse over the planar surface channel.
    Optics

    DISPLAYS: Electrofluidic display uses brilliant color pigments

    Gail Overton
    July 1, 2009
    Researchers at the University of Cincinnati and Sun Chemical (both in Cincinnati, OH) have developed a lithographically fabricated electrofluidic display that uses visually brilliant...
    Th Laa10 01
    Detectors & Imaging

    LaAlO3 deep-UV photodetector is naturally solar-blind

    July 1, 2009
    The solar-blind properties of lanthanum aluminate (LaAlO3), as well as its large bandgap energy of 5.6 eV, make it a good candidate material for deep-UV photodetectors.
    (Courtesy of UCLA)
    The STEAM camera was used for real-time imaging of laser ablation (a), revealing multiple two-dimensional (2-D) real-time images with a temporal resolution of 163 ns and shutter speed of 440 ps (b). Changes in sample surface reflectivity due to the laser-induced mass ejection are evident after the excitation pulse hits the sample at 50 ns. The time-sequenced surface reflectivity shows that the time delay between the pulse excitation and the sudden decrease in the surface reflectivity correlates with the ablation process (c); depth profile measurements (d) indicate that the silicon-on-insulator layer was exposed.
    Detectors & Imaging

    HIGH-SPEED IMAGING: World’s fastest camera images with time-domain data stream

    Gail Overton
    July 1, 2009
    Researchers at the University of California, Los Angeles (UCLA; Los Angeles, CA) have developed a real-time camera using a serial time-encoded amplified imaging technique that...
    Optics

    Nanostructured top layer enables wideband antireflection coatings

    July 1, 2009
    Wideband antireflection (AR) coatings—those for which the ratio of the upper wavelength limit to the lower wavelength limit is greater than 2—are difficult to fabricate, especially...
    Th Uses 01
    Test & Measurement

    Q-SWITCHED LASERS: Uses proliferate for high-energy picosecond UV lasers

    July 1, 2009
    High-energy, ultrashort-pulse ultraviolet lasers are useful for many practical applications—for example, fabrication of solar cells and flat-panel displays, 3-D information storage...
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    Detectors & Imaging

    TERAHERTZ DETECTORS: Quantum dots enable integrated terahertz imager

    July 1, 2009
    A highly sensitive and frequency tunable terahertz detector based on carbon nanotube quantum dots is the main ingredient for a near-field terahertz imaging system in which all...
    (Courtesy of University of Illinois at Urbana-Champaign)
    FIGURE 1. Optical frequency upconversion of femtosecond pulses is performed via intermodal four-wave mixing from a large-mode-area microstructured fiber (left) and via the Cherenkov radiation from a small-mode-area microstructured fiber (right). Vertical arrows represent the pump wavelength; the insets represent the far-field images of the exiting light from the fibers.
    Fiber Optics

    SPECIALTY FIBERS: Targeted pulse-energy routing in fiber drives nonsupercontinuum applications

    Stephen A. Boppart
    July 1, 2009
    While routing femtosecond pulse energy to a broadband spectrum in optical fibers is important, many emerging nonsupercontinuum applications require selective routing of the pulse...
    (Courtesy of Nonlinear Control Strategies)
    Modeled and experimental output powers and wavelength shifts for a 1040-nm-emitting VECSEL agree closely.
    Software

    LASER DESIGN: Software models laser diodes with no iteration

    John Wallace
    July 1, 2009
    A laser-diode-simulation software package introduced by Nonlinear Control Strategies (NLCSTR; Tucson, AZ) is quite a bit more intricate than the laser-diode modeling software ...
    Research

    Millihertz-linewidth laser could make the best clocks more precise

    July 1, 2009
    A theoretical proposal by scientists at JILA (which is jointly operated by the National Institute of Standards and Technology and the University of Colorado, both in Boulder, ...
    Lasers & Sources

    First CW ruby laser is path to CW UV source

    July 1, 2009
    Researchers at Klastech (Dortmund, Germany) have developed the first continuous-wave (CW) all-solid-state ruby laser at 694.3 nm, with an output power of greater than 100 mW—the...
    (Courtesy of Giant Magellan Telescope—Carnegie Observatories)
    FIGURE 1. Seven 8.4 m disks will make up the 24 m of the Giant Magellan Telescope. The concave secondary focuses light through a central hole to instruments mounted on the back of the primary support, with a compensating lens correcting for aberrations.
    Optics

    PHOTONIC FRONTIERS: MONSTER GROUND TELESCOPES: Bigger is better for ground telescopes: Super-giants will reach 24 to 42 m

    Jeff Hecht
    July 1, 2009
    Three super-giant ground telescopes planned to begin operation in 2018 have apertures two to four times larger than today’s biggest optical instruments.