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  • Volume 40, Issue 12

    • Volume 40, Issue 12

    More content from Volume 40, Issue 12

    FIGURE 1. The signal of a scattering-type scanning near-field optical microscope is generated by modulating the effective polarizability between the tip and the surface.
    When the ultrathin metallic needle used in an atomic-force microscope is exposed to a focused beam of light, the radiation acts as a radio wave.
    Dec. 1, 2004
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    Ti:sapphire laserClick here to enlarge imageThe TIS-SF-07 Ti:sapphire laser can serve as a multifunction source of single-frequency, tunable, CW radiation in applications such...
    Dec. 1, 2004
    FIGURE 1. The cross-disciplinary nature of nanotechnology demands a cross-disciplinary approach to marketing.
    If there ever has been a field to raise confusion and suspicion in the photonics industry, it is nanotechnology, in which marketing may ultimately pose a greater challenge than...
    Dec. 1, 2004
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    Walk across a parking lot at noon, stand next to a window on a summer day, or sit next to a warm computer while writing an article.
    Dec. 1, 2004
    Dave Welch
    recent development in photonics-the advent of the large-scale photonic integrated circuit (PIC)-will fundamentally alter the assumptions driving telecom system design, and will...
    Dec. 1, 2004
    The U.S. Department of Energy has selected more than three dozen projects to receive some $75 million in funding for research that could speed up the development of hydrogen-fueled...
    Dec. 1, 2004
    Researchers at the University of Rochester Laboratory for Laser Energetics (LLE; Rochester, NY) have developed a remotely operated stand-alone streak camera with comprehensive...
    Dec. 1, 2004
    Digital imaging has become a major market driver, affecting almost everything from storage to communications according to Fred Welsh, recently retired from the Optoelectronics...
    Dec. 1, 2004
    Japanese court dismisses lawsuit against CorningA Japanese court dismissed a lawsuit filed by Furukawa Electric Co. (Tokyo, Japan) against Corning Cable Systems International,...
    Dec. 1, 2004
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    Well-known techniques for detecting traces of explosives for security purposes include mass spectrometry and x-ray detection; an active area of research is the use of terahertz...
    Dec. 1, 2004
    Although C60 molecules have been used to make nonlinear optical materials before (reference numbers on the x axis refer to specific examples), the nonlinear response (y axis) has always fallen into a region below an experimentally determined limit (the lower of the two bars). The previously unreachable space between the bars has been known as the quantum gap. It has now been demonstrated that approaching the fundamental physical limit-getting into this quantum gap-is achievable.
    Scientists at the University of Toronto (Toronto, Ont., Canada) and Carleton University (Ottawa, Ont., Canada) have demonstrated the first material that approaches fundamental...
    Dec. 1, 2004
    Laser-induced-breakdown spectra were taken of normal (top) and malignant (bottom) liver tissue of a dog. Intensity ratios of some peaks can be used to check for cancer.
    Researchers from Mississippi State University (MSU; Starkville, MS) believe they can diagnose and classify cancer in vivo by determining the intensity ratio of trace elements ...
    Dec. 1, 2004
    One variation of laser wakefield acceleration to form monoenergetic beams of electrons with low energy spread is to use forced wakefield acceleration by carefully controlling plasma density and laser pulse length. Laser pulses are focused onto the edge of a jet of helium gas and the energy spectrum of the electrons evolves over time. At time 1, some low-energy electrons are created by self-focusing of the laser pulse. The laser pulse front begins to strengthen due to the forced wakefield mechanism and at time 2 the plasma wavelength begins to increase to the point where transverse wave-breaking takes place. At time 3, plasma oscillations behind the initial one also break, resulting in multiple groups of accelerated electrons. As they travel further to time 4, the electron bunches dephase with respect to the plasma wave, causing energy spread. By controlling the laser pulse length and increasing the plasma density over a shorter region, the monoenergetic bunch of electrons can be isolated.
    Research teams in England, the United States, and France have independently achieved breakthroughs in plasma-based particle accelerators that could eventually lead toward realization...
    Dec. 1, 2004
    Optoelectronic fibers can act as photodetectors or allow simultaneous transmission of photons and electrons. A preform for the photodetecting fiber (upper left) was drawn into fiber with a solid, highly photoconductive optical core surrounded by four tin electrodes, forming the photodetective element (upper right). A second fiber type is used for simultaneous electron-photon transport and in cross section consists of a hollow core, an omnidirectional mirror layer, and 8-mm-diameter embedded-tin conductors (bottom). The drawn fiber (bottom right inset) appears green in color due to reflection from the third-order (550-nm) photonic bandgap of the omnidirectional mirror.
    Optoelectronic devices owe their functionality to the combination of conducting, semiconducting, and insulating materials, and are typically manufactured in wafer-based processes...
    Dec. 1, 2004
    Optical-fiber sensors, such as this system being installed in an oil well, are often used to determine temperature, pressure, and other properties in down-hole environments. A carbon coating protects the fiber from high-partial-pressure molecular hydrogen, which darkens fiber.
    Optical fibers are useful in "down-hole" energy applications (which include oil, gas, and geothermal wells), serving either as data conduits or sensors.
    Dec. 1, 2004
    SLAC
    FIGURE 1. The design of the Mark2 vertex detector at Stanford Linear Accelerator Center established a paradigm for vertex detectors constructed of concentrically arranged silicon strip detectors [1].
    The European Organization for Nuclear Research (CERN; Geneva, Switzerland) celebrated its 50th anniversary this year, which also happened to be the 25th anniversary of the first...
    Dec. 1, 2004
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    A subwavelength grating and variable reflector proposed by researchers at Sandia National Laboratories (Albuquerque, NM) last year has been fabricated and demonstrated as a laterally...
    Dec. 1, 2004
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    In the sport of track cycling, medals are often decided by time differences of a small fraction of a second.
    Dec. 1, 2004
    A hollow rectangular core in an integrated optical waveguide measures 3.5 × 12 µm. The top ridge layer, intended for lateral confinement by effective-index guiding, measures 0.57 µm high by 5 µm wide (left). The intensity profile (full width at half maximum) of the mode propagating in the waveguide is 1.32 µm in the transverse direction and 6.4 µm in the lateral direction for a mode area of 6.64 µm2 (right).
    A desire to optically detect molecules one at one time has led researchers at the University of California, Santa Cruz (UC Santa Cruz), and at Brigham Young University (Provo,...
    Dec. 1, 2004
    M. Saif Islam and colleagues at the Quantum Science Research group of Hewlett-Packard Laboratories (Palo Alto, CA) have developed a solution to the long-standing issue of interconnecting 1-D semiconductor nanowire devices with conventional integrated-circuit elements, using processes compatible with mass manufacturing. They fabricated two opposing vertical and electrically isolated semiconductor surfaces using optical lithography along with wet and dry etching. Then they grew lateral nanowire devices from one surface and epitaxially connected them to the other, forming mechanically robust bridges. The work was presented in the conference on nanosensing at Optics East 2004.
    Optics East 2004, sponsored by SPIE, the International Society for Optical Engineering, was held Oct.
    Dec. 1, 2004
    Novalux sets sights on new marketsContrary to rumors floating around the industry in late October, Novalux (Sunnyvale, CA)-founded in 1998 to develop semiconductor-laser products...
    Dec. 1, 2004
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    Photonic A-to-D conversion directly samples multigigahertz signalsResearchers at HRL Laboratories (Los Angeles, CA) have combined photonic and indium phosphide heterojunction ...
    Dec. 1, 2004
    StockerYale to acquire Navitar for $25 millionStockerYale (Salem, NH) reached an agreement in principle to acquire Navitar (Rochester, NY) and its California subsidiary, Navitar...
    Dec. 1, 2004
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    Astronomers have inferred the existence of more than 120 planets outside the solar system by observing Doppler shifts in stellar spectra induced by planets gravitationally perturbing...
    Dec. 1, 2004
    UCF gets $1.5 million grant for photonics labsA $1.5 million grant from the U.S. Economic Development Administration will allow the University of Central Florida (UCF; Orlando...
    Dec. 1, 2004
    FIGURE 1. Dual-core fiber used in fiber lasers collects pump light in an outer core (or inner cladding), designed to pump rare-earth ions in the single-mode inner core. Fiber Bragg gratings in the inner core form the laser cavity.
    Major trends include high powers, coherent beam combination, ultrafast pulses, Q-switching, Raman lasers, and new materials.
    Dec. 1, 2004
    FIGURE 1. A conventional digital camera captures an image of a broadly illuminated field of view by collecting light scattered by spots in the field of view and imaging it through a lens and aperture to a conjugate light sensor element (top). An image is formed by repeating the process in parallel, with a small portion of light from each spot simultaneously imaged onto each of a typically large array of corresponding light sensors. In the laser camera a laser beam illuminates a single spot while a large-NA, nonimaging detector receives the scattered light energy and converts it to an electrical signal (bottom). An image is created by repeating the process sequentially-the beam is moved to illuminate the next spot and the scattered energy again measured.
    An innovative imaging platform has been developed that uses scanned beams of light and is in effect a versatile laser camera.
    Dec. 1, 2004
    FIGURE 1. A nine-element objective is corrected from 266 to 800 nm (top); it has an NA of 0.9, a field size of 0.13 mm, and is optimized to minimize the manufacturing tolerances and has reduced central obscuration. The objective has a standard object-to-flange distance of 45 mm. A seven-element objective is corrected from 266 to 800 nm (bottom); it has an NA of 0.9 and a field size of 0.13 mm.
    Many microscopy applications can benefit from broadband deep-UV (DUV) imaging, some of which also require immersion, cover glass correction, or operation over a wide temperature...
    Dec. 1, 2004
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    Microarrays are playing a critical role in genomic, proteomic, and drug-discovery research. Scientists are now integrating the illumination and detection processes on single chips...
    Dec. 1, 2004