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    • Volume 43, Issue 2

    More content from Volume 43, Issue 2

    FIGURE 1. In a multiphoton-microscopy image of mature glomerulus from an adult rat, podocytes are labeled with antivimetin (brown) and the nuclei with DAPI (blue). This image was taken using a Spectra-Physics femtosecond Ti:sapphire laser (Mai Tai) tuned to 800 nm.
    Confocal microscopy may be the current standard for studying live cells, but multiphoton is the rising star.
    Feb. 1, 2007
    Bacteriorhodopsin (bR) is a photochromic biological molecule that has promise for use in all-optical switches and other photonic components; however, bR is transparent in the ...
    Feb. 1, 2007
    All-optical information processing on a chip will require controllable buffering of optical signals.
    Feb. 1, 2007
    Researchers at the National Institute of Standards and Technology (NIST; Boulder, CO) and the National Renewable Energy Laboratory (NREL, Golden, CO) have demonstrated and verified...
    Feb. 1, 2007
    Researchers at École Polytechnique de Montréal (Montréal, QC, Canada) have developed a microstructured optical fiber from biodegradable and water-soluble materials that could ...
    Feb. 1, 2007
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    An international team of astronomers using NASA’s Hubble Space Telescope has created the first three-dimensional map of the large-scale distribution of dark matter.
    Feb. 1, 2007
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    Physicists at Boston College (BC; Chestnut Hill, MA) have shown that a nanoscale coaxial waveguide can guide visible light.
    Feb. 1, 2007
    FIGURE 1. Aspheric subaperture-stitching interferometry can be used to measure the surface figures of aspheres such as this ellipsoid (conic), which has a 100 mm aperture diameter, a base radius of -226 mm, and approximately 12 µm of aspheric departure. The asphere is fabricated from lightweighted silicon carbide with silicon cladding.
    Distributed, mild aspheric surfaces and subaperture-stitching interferometry combine to form a cost-effective approach to fabricating aspheric optics.
    Feb. 1, 2007
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    The diode-laser market was mixed in 2006, with revenues in some categories increasing significantly, and those in other categories showing substantial declines.
    Feb. 1, 2007
    FIGURE 1. The operation of the high-throughput three-dimensional detector (H33D) begins with a pulsed laser to excite the fluorescence of a sample. Fluorescence photons are collected by the imaging optics and interact with the photocathode, creating one photoelectron per photon that is amplified by an opposed multichannel plate to generate an electron cloud (cone shape). The position of the cloud is determined by a position-sensitive cross-delay line anode, in which charges propagate through the lines and are collected at both ends. Timing electronics convert the differences in arrival time into position information and the four photon coordinates (laser pulse nanotime τ, position x, y, and macrotime T) are processed and stored by a computer. In the setup, the fixed time delay is δ, signal-propagation velocity v > 1 mm/ns, and the sensitive area has a diameter of 1 inch.
    A high-throughput three-dimensional detector combines the advantages of wide-field detectors and high-temporal-resolution point detectors, proving instrumental for single-molecule...
    Feb. 1, 2007
    Ifor Samuel, a physics professor at the University of St. Andrews, has developed an OLED-based “sticking plaster” that simplifies the use of photodynamic therapy in the treatment of skin cancer. In the proof-of-principle prototype, the 2 cm polymer OLED light source is attached to the skin with standard medical tape.
    Organic light-emitting diodes (OLED) have garnered much attention in recent years because of their potential to revolutionize lighting and displays.
    Feb. 1, 2007
    FIGURE 1. Piezoelectric crystal increases in length L + ΔL and decreases in diameter D + ΔD (ΔD is negative) with an applied voltage V (top, left). Stacked piezoelectric elements increase total displacement for voltage V applied in parallel to each element (top, right). A lever mechanism extends piezoelectric displacement into the 10s or 100s of microns (bottom).
    Accurate positioning in laser and photonics applications generally relies upon converting an applied voltage into a very accurate displacement.
    Feb. 1, 2007
    Laser processing of the back side of a solar cell creates an emitter and base region (inset shows a scanning-electron micrograph of a structured silicon surface with separated contact levels). A wet chemical-etching step removes silicon crystal damage (due to laser ablation) that can reduce carrier lifetime, resulting in a highly efficient solar cell with greater than 22% conversion efficiency.
    Solar cells made from crystalline silicon (Si) dominate the solar photovoltaic market.
    Feb. 1, 2007
    A scanning-electron micrograph reveals uniform diameters and smooth surfaces in p-type ZnO nanowire arrays.
    Before the development of gallium nitride (GaN) blue light-emitting-diodes (LEDs) by Shuji Nakamura, zinc oxide (ZnO) was broadly studied as a possible material for blue emitters...
    Feb. 1, 2007
    Driven by an actuator (top, gray), two pusher rings (gold and violet) deform a flat mirror into a paraboloid, compensating for thermal-lens effects occurring in a high-energy-laser rod amplifier. The focal length of the mirror can be varied from infinity down to 5 m (bottom). The interferometrically measured wavefront profile has the desired paraboloidal shape (bottom, 3-D color plot).
    To counter thermal lensing in high-energy-laser rod amplifiers, researchers at Sandia National Laboratories (Albuquerque, NM) have developed a deformable mirror that does one ...
    Feb. 1, 2007
    Continuous demagnetization cools chromium atoms in an optical dipole trap while minimizing the loss of atoms. The black squares show the evolution of temperature (top) and the number of atoms in the trap (bottom) as the magnetic field is decreased from 250 to 50 mG; the red circles are the same quantities when the field is kept constant.
    Laser cooling of atomic and molecular gases has helped scientists explore the boundaries of low-temperature physics—for example, by creating Bose-Einstein condensates (whose uses...
    Feb. 1, 2007
    A card-to-backplane optical interconnect uses an array-waveguide evanescent coupler (AWEC) to connect the card signal directly to the backplane, a more cost-effective technique that eliminates the need for the micromirrors that are typically required to make the 90º turn. Preliminary testing demonstrates operation above 2.5 GHz for the AWEC ribbons.
    Interconnects for card-to-backplane connections and motherboards will soon be required to handle multigigahertz speeds as computing power increases; however, electronic interconnects...
    Feb. 1, 2007
    The ratios of group (vg) and phase (vp) velocities to the speed of light (c) of a surface-plasmon polariton on a metal nanorod vary as functions of gain (top left), frequency (bottom left), and radius (top and bottom right).
    Optical gain in subwavelength waveguides is generally used for compensating losses.
    Feb. 1, 2007
    In an experimental setup for position detection using hyperacuity (top), a point source at infinity or on an edge at a finite distance is used as the object within the field of view of an artificial apposition compound eye (APCO; bottom). Rotating the ensemble of the APCO, the microscope objective, and the CCD camera simulates object movement.
    Researchers at the Fraunhofer Institute for Applied Optics and Precision Engineering (IOF) and at Friedrich Schiller University Jena (both in Jena, Germany), are applying hyperacuity...
    Feb. 1, 2007
    A study undertaken by TeraView and the FDA looked at coating-thickness variations on Internet-sourced pharmaceutical products, revealing large variations in tablet-coating thickness within the same tablet and between tablets.
    Researchers at TeraView (Cambridge, England) are using terahertz technology to help regulatory authorities, law-enforcement agencies, and the pharmaceutical industry screen for...
    Feb. 1, 2007
    In the laser-doping process, a SiC wafer is placed in a gaseous chamber that contains n- and p-type dopant compounds. As the chamber is translated under a laser beam, the gas decomposes at the laser-heated spot and the dopant atoms diffuse into the wafer, creating p-n junctions that are the basis for optoelectronic components such as LEDs.
    Researchers at The Center for Research and Education in Optics and Lasers (CREOL) at the University of Central Florida (Orlando, FL) and at AppliCote Associates (Sanford, FL) ...
    Feb. 1, 2007
    Executives from Avanex (Fremont, CA) and Bookham (San Jose, CA) agree that optical-component suppliers are finally seeing an increase in demand for new technology, rather than...
    Feb. 1, 2007
    First Solar (Phoenix, AZ) raised $400 million in its initial public offering (IPO) of 20 million shares of common stock at $20 per share.
    Feb. 1, 2007
    Optical components, subsystems, and photonics systems provider OFR (Caldwell, NJ) has been acquired by Thorlabs (Newton, NJ).
    Feb. 1, 2007
    Coherent (Santa Clara, CA) signed a licensing agreement with Osram (Munich, Germany) for the use of Coherent’s optically pumped semiconductor lasers for projection displays.
    Feb. 1, 2007
    The scientific market for lasers has been a mainstay of optics and photonics ever since the laser was invented.
    Feb. 1, 2007
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    Product developers must ensure the performance of CMOS sensors and modules.
    Feb. 1, 2007
    FIGURE 1. An integrated optical system for monitoring via image analysis includes mechanical and optical components, an image-acquisition system, a hardware-based image-processing unit, and image-processing software.
    Combining infrared- and visible-spectral-range sensors with a stereo camera system can yield a more effective traffic-management system for busy city streets.
    Jan. 15, 2007