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    • Volume 44, Issue 6

    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.
    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...
    June 1, 2008
    A 50 mW analog modulated green laser links the Anglican and Catholic cathedrals in Liverpool, England, as part of the European City of Culture 2008. The laser will carry audio between the two buildings as well as being a visible link between the two faiths.
    Controlling green lasers with the kind of finesse with which red lasers are routinely run is no mean feat.
    June 1, 2008
    (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.
    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...
    June 1, 2008
    (Courtesy of Australian National University, Canberra)
    FIGURE 1. A nonlinear tunable metamaterial (for microwaves) is based on a series of printed-circuit boards with split-ring resonators and wires arranged to form a superlattice.
    A research team at the Nonlinear Physics Centre of the Australian National University in Canberra, reports that it has produced the first nonlinear tunable metamaterial and, using...
    June 1, 2008
    (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).
    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...
    June 1, 2008
    (Courtesy of Archer OpTx)
    FIGURE 1. A 19 mm molded glass aspheric lens is tested using a Zygo XP/D interferometer.
    Ultra-high-precision molding of aspheric optics in volume production is best accomplished with careful attention to glass selection, tolerancing, processing, and testing.
    June 1, 2008
    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]
    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.
    June 1, 2008
    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).
    Photoconductive switch and photomixer technologies have been commercialized for terahertz applications and are improving with advances in the photoconductive materials and the...
    June 1, 2008
    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.
    Today’s organic semiconductor lasers are optically pumped laboratory devices. Will tomorrow’s be electrically excited or improved versions of the optically pumped lasers?
    June 1, 2008
    (Courtesy University of Illinois at Urbana-Champaign)
    The limit for quantum dense-coding techniques using linear optics and the polarization state of a pair of entangled photons is 1.58 bits. However, if both polarization and orbital angular momentum are applied to entangled photons using nonlinear crystals in a process called hyperentanglement, the channel capacity of a quantum-information network can be increased to 1.63—above the standard dense-coding scheme.
    Quantum dense coding allows a sender of digital information (Bob) to communicate a maximum of two bits of classical information to a receiver (Alice) by transmitting only a single...
    June 1, 2008
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    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’...
    June 1, 2008
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    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...
    June 1, 2008
    (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.
    Enhancements in diode pump efficiencies, wavelengths, and on-chip gratings have dramatically improved laser-system compactness, efficiency, power, and beam quality.
    June 1, 2008
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    The annual PhAST/Laser Focus World Innovation Award honors the most timely, groundbreaking products in the field of laser science.
    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.
    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...
    June 1, 2008
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    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...
    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...
    June 1, 2008
    Fujifilm Dimatix (Santa Clara, CA), supplier of drop-on-demand inkjet printheads for industrial applications, announced that its cartridge-based Dimatix Materials Printer was ...
    June 1, 2008
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    The Series 8000 793-MFP fiber-coupled diode lasers deliver up to 3 W of CW output power at 793 nm from a 100-µm-core 0.
    June 1, 2008
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    It is a painful reality that nations must carefully regulate the export and import of certain “dual-use” technologies that could be used as weapons of war.
    June 1, 2008
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    Our technonology has been validated in the marketplace and we are now looking to be acquired.
    June 1, 2008
    Novel lenses and optics make light-field cameras viable.
    June 1, 2008
    What really struck me when reading about these researchers was how necessarily simple many of these experiments were.
    June 1, 2008
    Speaking to attendees at the recent Photonics Europe meeting in Strasbourg, France, Ronand Burgess of the European Commission’s Photonics Unit said that photonics in Europe grew...
    June 1, 2008
    Scientists and engineers across Europe have joined forces in a unique collaborative effort to develop a new generation of high-brightness lasers that will transform the fields...
    June 1, 2008
    Planar-lightwave-circuit supplier for the fiber-to-the-home (FTTH), metro, and long-haul telecommunication markets, Enablence Technologies (Ottawa, ON, Canada) signed a definitive...
    June 1, 2008
    The Presidential Award for Excellence in Mathematics and Science Teaching is the highest recognition that a mathematics or science teacher can receive for outstanding teaching...
    June 1, 2008
    Coherent (Santa Clara, CA) entered into a definitive agreement to sell certain assets of Coherent’s Auburn Optics manufacturing operation to Research Electro-Optics (Boulder, ...
    June 1, 2008
    (Courtesy of Weizmann Institute of Science)
    In a basic configuration for four fiber lasers in a 2-D array, beams are coherently combined by an interferometric combiner in free space, producing two beams. These now linearly oriented beams are then spectrally combined into one beam using a linear diffraction grating, resulting in efficient power scaling.
    Two methods for combining the output of several fiber lasers for the purpose of power scaling are spectral addition and coherent addition.
    June 1, 2008
    (Courtesy Harvard University)
    The experimental setup for the zone-plate tweezer (inset), which is activated by the 976 nm laser-diode source, includes a second optical trap at 633 nm to load the zone-plate trap effectively, and a 532 nm laser to excite fluorescence in the trapped particles for the purpose of imaging.
    The forces exerted by tightly focused laser beams can create optical tweezers for the purpose of manipulating small particles.
    June 1, 2008
    (Courtesy of Colorado State University)
    Triangular patterns containing varying amounts of oxides of Co, Fe, Al, and Cs were fabricated on glass; each triangle contains a different single-metal oxide at each corner, with varying mixes elsewhere in the triangle (top). A triangle consisting solely of copper oxide is an experimental reference. Under 532 nm laser light, certain regions in the triangles show high p-type photocurrent response (bottom)—an indicator of the high effectiveness of those particular multimetal oxide mixes as solar-photoelectrolytic materials.
    While silicon and other photovoltaic solar cells get much press and are widely used, another lesser-known approach to solar-cell technology holds great promise, in particular ...
    June 1, 2008
    (Courtesy of Stanford University)
    FIGURE 1. Serving as the core structure of a focal-plane array, a plane of silicon is made flexible by the addition of slots. Shaped properly, the slots result in thin springs that link each array element to its four neighbors.
    As every camera-lens designer knows, the need to produce flat image planes drives up the mass and complexity of camera optics.
    June 1, 2008
    (Courtesy of V. Zéninari)
    The QCL spectrometer measured concentrations of atmospheric N2O as the air temperature varied between 9ºC and 15ºC. Gray points correspond to measurements taken every 5 s while black points correspond to results averaged over 30 successive results.
    The ability to measure the gases that contribute to global warming, such as methane (CH4), carbon dioxide (CO2), chlorofluorocarbons (CFCs), and nitrous oxide (N2O), is important...
    June 1, 2008
    (Courtesy of University of California, Berkeley)
    A matter-wave cloaking system involves super-cooled Rb atoms within a three-dimensional laser-based optical lattice. The system causes matter waves traveling through the medium to bend around the atoms inside as though they aren’t there.
    Invisibility cloaking of matter on the scale of the Romulans and Harry Potter is still firmly science fiction, but recent experiments have demonstrated optical metamaterials with...
    June 1, 2008
    FIGURE 1. A complex optical train is typically used for a digital-light-processing projection system.
    An integrated monolithic assembly can replace the complex optical train that magnifies and projects a microdisplay's image, resulting in improved performance, minimized aging ...
    May 30, 2008