• Subscribe
  • Podcasts
  • Videos
  • Webinars
  • White Papers
  • Buyer's Guide
  • Get Published!
  • 2024 Innovators Awards
  • Back Issues >
  • Laser Focus World >
  • Volume 44, Issue 6

    • Volume 44, Issue 6

    Lasers & Sources

    The first electrically injected blue-emitting VCSEL operates at 77 K

    June 1, 2008
    Creation of the first directly electrically pumped vertical-cavity surface-emitting laser (VCSEL) has been reported by a group of scientists at National Chiao Tung University ...
    Detectors & Imaging

    Noncontact linear scanner has 3 m span

    June 1, 2008
    Engineers at CMOS Sensor (Cupertino, CA) have developed an industrial linear scanner (ILS) built from a long, contiguous row of CMOS linear image sensors.
    Th 0806lfwnb1
    Fiber Optics

    New optical fiber remains transparent under extreme gamma radiation

    June 1, 2008
    Engineers at AFO Research (Glendale, CA) have developed a new type of fluorophosphate-glass optical fiber (179 µm fiber diameter, 284 µm acrylate-coating diameter) that has been...
    Detectors & Imaging

    New nonlinear crystal spans mid-IR region

    June 1, 2008
    Recognizing that nonlinear oxide-based crystals can only shift the output of 1.06 μm and 1.55 μm solid-state lasers up to approximately 4 μm wavelengths, while chalcopyrite crystals...
    Th 0806lfwnb3
    Research

    Popcorn-shaped nanocrystallites double efficiency of dye-sensitized solar cells

    June 1, 2008
    Inexpensive and efficient solar cells are the “holy grail” in photovoltaic research, and a new type of film composed of tiny balls may significantly improve efficiency without...

    More content from Volume 44, Issue 6

    (Courtesy of Chiral Photonics)
    FIGURE 1. Side and face images of the twisted fiber show single- (top) and double-helix (bottom) gratings.
    Optics

    FIBER SENSING - Chiral-fiber gratings sense the environment

    June 1, 2008
    Twisted fibers create chiral gratings that can facilitate the deployment of fiber sensors for sensing liquid level, temperature, elongation, axial twist, and pressure in harsh...
    FIGURE 1. The calibrated output power is plotted (above) for an erbium arsenide: gallium arsenide (ErAs:GaAs) photomixer (red circles) and compared to a legacy low-temperature-grown GaAs device (blue squares). A square spiral antenna is used for photomixers and photoconductive switches (right).
    Lasers & Sources

    Terahertz Sources - Laser advances drive THz photoconductive source technology

    June 1, 2008
    Photoconductive switch and photomixer technologies have been commercialized for terahertz applications and are improving with advances in the photoconductive materials and the...
    Th 0806lfwinnov Coherent
    Optics

    INNOVATION AWARD - Coherent wins PhAST/LFWInnovation Award

    June 1, 2008
    The annual PhAST/Laser Focus World Innovation Award honors the most timely, groundbreaking products in the field of laser science.
    (Courtesy of Stanford University)
    The liver of an anesthetized nude mouse is imaged using Raman spectroscopy and Raman-active nanoparticles that are trapped specifically in the liver cells.
    Research

    RAMAN SPECTROSCOPY: Raman technique improves imaging 1000 times

    Gail Overton
    June 1, 2008
    A new noninvasive Raman-spectroscopy technique could enable the detection of even the most minute malignant tissues if applied to human use in surgical or endoscopy applications...
    (Courtesy of Archer OpTx)
    FIGURE 1. A 19 mm molded glass aspheric lens is tested using a Zygo XP/D interferometer.
    Optics

    Aspherics - Design considerations finesse asphere lenses

    June 1, 2008
    Ultra-high-precision molding of aspheric optics in volume production is best accomplished with careful attention to glass selection, tolerancing, processing, and testing.
    Research

    Clusters of microparticles enable sensitive new optical biosensor

    June 1, 2008
    Whispering-gallery-mode (WGM) excitation, a phenomenon that occurs when light is trapped in a resonant cavity, has many applications in lasers, filters, and sensors.
    FIGURE 1. Optical pumping of a polymer thin film sandwiched in a Fabry-Perot cavity shows that gain can be high, but power is low because the cavity is very thin.
    Lasers & Sources

    Photonic Frontiers: Organic Semiconductor Lasers - The pump is the challenge

    Jeff Hecht
    June 1, 2008
    Today’s organic semiconductor lasers are optically pumped laboratory devices. Will tomorrow’s be electrically excited or improved versions of the optically pumped lasers?
    Th 0806lfwnb2
    Research

    Quantum dots lase in levitated microdrop

    June 1, 2008
    By levitating a spherical liquid microdrop doped with quantum dots in an electrodynamical trap and accessing the droplet’s surface-resonant modes, researchers at the Max-Planck...
    A semiconducting-polymer laser is pumped with an InGaN LED (top; Courtesy of Graham Turnbull). Organic semiconductors can have various colors, and can be dissolved and made into various shapes (bottom; Courtesy of Ifor Samuel). [1]
    Optics

    ORGANIC LASERS: LED pumps polymer laser

    D. Jason Palmer
    June 1, 2008
    Polymer lasers have long promised cheap, simple fabrication and broad tunability but have so far suffered from the need for an external laser pump source.
    (Courtesy of QPC Lasers)
    FIGURE 1. Fiber-laser manufacturers demand spatial beam profiles from a “cladding-free” 100-µm-core fiber-coupled module to avoid power leakage and component damage.
    Optics

    Diode-Laser Pumps - High-power diode lasers advance pumping applications

    June 1, 2008
    Enhancements in diode pump efficiencies, wavelengths, and on-chip gratings have dramatically improved laser-system compactness, efficiency, power, and beam quality.
    Th 0806lfw01f1
    Research

    EUROPEAN REPORT - Photonics drives growth in the EU

    Mark Zacharria
    June 1, 2008
    The EU’s Framework Programme 7 recognizes photonics as one of the essential drivers for Europe’s future economic growth. Increased funding, along with the European Commission’...
    (Courtesy University of Cincinnati)
    The organic white ELiXIR pcLED emits a bluish-white light. In operation, it gives a “near ideal” conversion efficiency of 0.99, via a remote hemispherical shell with semitransparent phosphor, but a slightly narrower spectrum (bottom left).
    Lasers & Sources

    LEDs: Phosphor-converted white LEDs have almost no conversion loss

    Valerie Coffey-Rosich
    June 1, 2008
    White-light light-emitting diodes (LEDs) are typically created either from blue- or near-ultraviolet-emitting chips coated with a yellow phosphor, or from red-green-blue systems...
    Research

    Ultrabright source produces MeV-class gamma rays

    June 1, 2008
    Researchers at Lawrence Livermore National Laboratory (Livermore, CA) have announced first light from a novel ultrabright gamma-ray source they call T-REX (Thomson-Radiated Extreme...
    Research

    Stokes’ polarization theorem proven to be flawed

    June 1, 2008
    In 1852, George Gabriel Stokes appeared to have proven the theorem that any light beam is equivalent to the sum of two independent light beams, one of which is completely polarized...
    Th 0806lfw5f1
    Optics

    Low-Scatter Optical Surfaces - Chemical-mechanical polishing shines mirrors

    June 1, 2008
    A new chemical-mechanical polishing technique extends the use of monolithic aluminum optics beyond the infrared and into the visible and ultraviolet spectrum for imaging and beam...