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    • Volume 44, Issue 7

    More content from Volume 44, Issue 7

    FIGURE 1. An experimental one-dimensional interferogram from a FTIR-FPA is symmetrized by duplicating and flipping it about the zero-path-length point on the plot. A Fourier transform is then taken of this data to obtain a spectral curve.
    If a handheld spectrometer could be created that operated without the need for a spectral-scanning mechanism, its resulting simplicity and low cost would greatly expand its practical...
    July 1, 2008
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    Once the job of electrons, stimulating heart cells is now being done by photons.
    July 1, 2008
    FIGURE 1. A high-resolution spectrometer used in combination with a telescope measures changes in the wavelength of light coming from a star over the course of days, months, and years. The change in color is caused by the Doppler shift of the light, resulting from the star orbiting a common center of mass with a companion planet (referred to as stellar wobble). Because of the large size of the star in comparison to the planet, the center of mass of a planet-star pair is often located within the star.
    Detecting the exceedingly small Doppler shifts from parent stars and orbiting planets in other solar systems will require extremely sensitive instruments.
    July 1, 2008
    (Courtesy of Fianium and Tampere University of Technology)
    FIGURE 1. A fiber laser can be used for pulsed laser deposition to fabricate smooth zirconium oxide films on silicon. The picosecond pulses allow deposition of amorphous films at room temperature and the high repetition rate enables the upscaling of the growth rate while maintaining the high quality of the deposited films. Growth rate is comparable to other pulsed vapor deposition methods and is in the range of a few nanometers per second.
    Although solid-state lasers will continue to play a role in microprocessing, the high repetition rate and high peak power of today’s ultrafast fiber lasers are getting noticed...
    July 1, 2008
    FIGURE 1. Three types of coherent beam combination include a common resonator keeps multiple laser elements in phase (top); an evanescent-wave coupling between closely spaced laser elements keeps their output in phase (center); and an active feedback loop, with wavefront sensors detecting the phase of each laser element fed by a master oscillator, then modulating the phase of each element (bottom).
    Efforts to scale the output power of a single-output laser inevitably run into limits.
    July 1, 2008
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    Imagers based on monolithic complementary metal-oxide semiconductors (CMOS) were first introduced as a competitor to charge-coupled-device (CCD) detectors more than a dozen years...
    July 1, 2008
    (Courtesy of Fraunhofer IPMS)
    FIGURE 1. Scanning-electron-micrograph images show a scanning grating chip; the size of the grating area is typically limited to 3 × 3 mm² because of process and mechanical limitations. The grating moves with a speed between 130 to 150 Hz.
    Hyperspectral imaging is used for a broad variety of applications ranging from the harvesting of agricultural goods to waste selection in recycling processes.
    July 1, 2008
    A single-core fiber doped with several rare-earth elements is pumped with either a Ti:sapphire laser at 804 nm (dotted curve) or a laser diode at 811 nm (solid curve); the fiber’s emission spectrum is largely similar in both cases.
    Optical-fiber-based broadband light sources are desirable for applications such as spectroscopy or optical coherence tomography because, being effectively point sources, they ...
    July 1, 2008
    A lasing spaser consists of a thin slab of a dielectric gain medium (center) underneath an array of asymmetric split-ring resonators. In a single translation cell of the array, asymmetric currents of plasmonic oscillations in phase with the other cells produce emission of spatially and temporally coherent light that propagates in a direction normal to the array. The arc angles of the nanowire segments, β1 and β2, determine the Q-factor and coupling intensity.
    A new type of nanoscale optical device called a lasing spaser combines metamaterials and spasers to create a versatile planar source of coherent radiation.
    July 1, 2008
    (Courtesy of University of Padua)
    In the satellite single-photon link, a fraction of the beam in the uplink path irradiates the satellite. The corner cubes on the satellite retroreflect a small portion of the photons in the laser pulse back to the Earth (in green).
    A quantum communications link in space is one step closer after Italian researchers successfully detected a single photon sent from Earth to a low-Earth-orbit satellite and back...
    July 1, 2008
    FIGURE 1. Several objective design forms can be used in IC inspection applications: (from left) all-fused-silica design is ideal for monochromatic applications; all-refractive design with CaF2 positive lenses and fused-silica negative lenses gives moderate bandwidth; a catadioptric design form with off-axis field can extend bandwidth; and an obscured, essentially all-reflective design offers wide bandwidth, with a large monolith that has one refractive and two reflective surfaces.
    Semiconductor inspection and yield-enhancing tools are pushing design of imaging objectives into the deep-ultraviolet part of the spectrum and high numerical apertures.
    July 1, 2008
    (Courtesy University of Tokyo)
    A near-field photochemical photodissociation process uses a 532 nm continuous-wave laser to reduce the 2.36 Å surface roughness of silica obtained with conventional chemical-mechanical polishing techniques (left) to only 1.37 Å (right).
    Conventional chemical-mechanical polishing (CMP) methods are typically used to obtain surfaces figured to sub-100-nm tolerances on optical and semiconductor materials for specialized...
    July 1, 2008
    (Courtesy of the Foundation for Research and Technology-Hellas)
    A scanning-electron micrograph of the actual device.
    Researchers at the University of Crete and the Foundation for Research and Technology-Hellas (both in Heraklion, Crete, Greece) have created an electrically pumped polariton light...
    July 1, 2008
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    Conduction-cooled, fiber-coupled 1550 nm diode-laser modules are based on single- or multibar configurations.
    July 1, 2008
    Steve Anderson, Laser Focus World editor-in-chief and associate publisher (center), presents the 2008 PhAST/Laser Focus World Innovation Award to Andrew Masters (right), a director of marketing at Coherent, for Coherent’s OPSL-577-3, an optically pumped semiconductor laser at 577 nm targeted for the treatment of age-related macular degeneration, as David Huff, vice president of marketing and business development for the Optoelectronics Industry Development Association, looks on. To view video interviews with award recipients, see www.laserfocusworld.com/resourcecenter/video.html.
    Despite mixed reviews from exhibitors on the show floor at the Conference on Lasers and Electro-Optics, Quantum Electronics and Laser Science Conference, and the Photonic Applications...
    July 1, 2008
    (Courtesy of Yokohama National University and CREST)
    Four of the airholes in a hexagonal nanolattice in a GaInAsP single-quantum-well wafer are shifted -- two laterally by 60 nm (Sx) and two longitudinally by 120 nm (Sy). The result is a nanolaser cavity that achieves continuous-wave lasing in the 1550 nm region when pumped by light at 980 nm. As the refractive index of the surrounding gas or fluid changes, the wavelength of the nanolaser changes, allowing monitoring of the index.
    Measuring the change in refractive index of a liquid induced by the entry of a foreign substance is one way to determine whether the liquid has become contaminated.
    July 1, 2008
    (Courtesy of the Capasso Lab, Harvard School of Engineering and Applied Sciences)
    One of the lasers in a bar with 10 terahertz laser sources is connected to the contact pad (left) by two thin gold wires. A 2-mm-diameter silicon hyperhemispherical lens is attached to the facet of the device to collimate the terahertz output. The emission frequency is 5 THz, corresponding to a wavelength of 60 µm.
    The terahertz region has long been described as the last frontier in the electromagnetic spectrum, with promises of endless applications in imaging, sensing, and security.
    July 1, 2008
    Larry Marshall, entrepreneur and budding venture capitalist, shares his thoughts and reflections on the venture-capital scene in his biweekly blog.
    July 1, 2008
    (Courtesy of Science Magazine and Robert Tandy)
    While a conventional laser cavity (left) has highly reflecting mirrors that trap light long enough for amplification by the gain medium (light blue) to be efficient, trapping of light in a random laser (right) is not achieved by mirrors, but by multiple scattering between subwavelength-size particles (red dots). In such a random medium, the light emitted by an atom (yellow) can make a roundtrip in an infinite number of loops. In the special case of a diffusive random laser, the scattering is so weak that without gain most of the light would escape before returning to its starting point. Because of this strong damping (leakage), the oscillation frequencies of such a system are not well-defined until lasing sets in and a number of well-defined, sharp oscillation frequencies appear, bearing no straightforward relationship to the strongly damped natural oscillations of the system without gain.
    Ten years ago, when a team of researchers led by Claire Gmachl and Federico Capasso at Bell Laboratories (Murray Hill, NJ) grabbed the cover of Science magazine with a paper on...
    July 1, 2008
    Physical Sciences (PSI; San Ramon, CA) was awarded two $600,000 Phase II Small Business Innovation Research (SBIR) contracts valued at $600,000 each by the National Aeronautics...
    July 1, 2008
    Kopin (Taunton, MA) was selected for a $600,000 solar-cell development contract from the National Aeronautics and Space Administration (Washington, DC), the second phase of a ...
    July 1, 2008
    Cambridge Display Technology (CDT; Cambridge, England) and Sumitomo Chemicals (Japan), providers of polymer organic-light-emitting-diode (P-OLED) devices, and Novaled (Dresden...
    July 1, 2008
    The Industrial Partnerships Office at Lawrence Livermore National Laboratory (LLNL) has found a way to accelerate the development of “disruptive” technologies that benefits both...
    July 1, 2008
    Semiconductor and microelectronics processing is big business for capital equipment makers—equipment sales reached $41.7 billion.
    July 1, 2008
    In these parlous days of rapidly escalating gas prices, academic and industrial researchers are frantically turning to improved and/or alternative energy sources.
    July 1, 2008
    1304qa Chang New
    Q: What can I do to grow a product-development engineering services business that serves customers in the Department of Defense and the defense industry? My partner and I enjoy...
    July 1, 2008