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  • Volume 40, Issue 12

    • Volume 40, Issue 12

    FIGURE 1. In a MEMS-tuned external-cavity diode laser, the gain-chip output is collimated by the lens, diffracted by the grating, and retroreflected along a path determined by the lens position. Frequency is tuned by rotating the mirror with the silicon MEMS actuator and measured using the filter and 50-GHz etalon signals. The laser components are assembled on a ceramic substrate, bonded to a thermoelectric cooler, and sealed in a hermetic butterfly package.
    Optics

    MEMS-tuned devices take on sensing and testing applications

    Dec. 1, 2004
    Grating-tuned external-cavity semiconductor lasers have served for many years as convenient, widely tunable laboratory laser sources and have found applications as diverse as ...
    FIGURE 1. Pharmaceutical tablets have essentially become highly engineered drug delivery systems. From left to right: Oros, an Alza-developed tablet used by Pfizer and others, retains its shape in gastric fluids and releases therapeutic doses through an osmotic aperture; inorganic or polymeric microspheres selectively release adsorbed drugs with selected target therapies at staggered concentrations and release rates to provide a complex therapeutic pattern in the bloodstream; a barrier-layer reservoir capsule refreshes the drug concentration in the upper chamber as the drug releases to maintain constant concentrations and provide long drug-level plateaus in the bloodstream; and a cored tablet sequentially delivers one drug at two distinct concentrations or delivers two different drugs back-to-back [7].
    Test & Measurement

    Hyperspectral imagers shed light on pharmaceutical processing methods

    Hassaun A. Jones-Bey
    Dec. 1, 2004
    The combination of a Food and Drug Administration (FDA) initiative promoting process analytical technology (PAT) and sizable financial risks and incentives in the pharmaceutical...
    FIGURE 1. A 0.3-µm2 defect in a 3-D multiple-quantum-well photonic crystal serves as a cavity that emits 1550-nm light.
    Research

    Illuminating achievements

    John Wallace
    Dec. 1, 2004
    Advances in manipulating light at nanoscopic levels, pushing the limits of high-power emitters, and imaging at levels beyond the pixel count of the human eye exemplify this year...
    FIGURE 1. A quantum-dot IR detector allows absorption of normal-incidence light, a result of three-dimensional confinement in quantum dots. A group of researchers from Northwestern University (Evanston, IL) will present information on the first indium phosphide-based quantum-dot IR detector during the Quantum Sensing and Nanophotonic Devices II conference. An atomic-force microscope (AFM) scan can reveals the structures of a group of InAs (indium arsenide) quantum dots in a 1 × 1-µm area grown in an InP (indium phosphide) substrate (left). The cylindrical structure of an individual quantum dot in the field is well defined (right).
    Research

    Photonics West 2005: Showcasing leading-edge technology

    Gail Overton
    Dec. 1, 2004
    This year's conference will offer attendees a close-up view of the best innovations in optoelectronics, biomedical optics, laser applications, and micro- and nanofabrication.

    More content from Volume 40, Issue 12

    Th 165048
    Research

    Newsbreaks

    Dec. 1, 2004
    Photonic A-to-D conversion directly samples multigigahertz signalsResearchers at HRL Laboratories (Los Angeles, CA) have combined photonic and indium phosphide heterojunction ...
    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.
    Research

    CONFERENCE REVIEW: Optics East features nanotechnology and ITCom

    Gail Overton
    Dec. 1, 2004
    Optics East 2004, sponsored by SPIE, the International Society for Optical Engineering, was held Oct.
    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.
    Fiber Optics

    Fiber lasers take off in diverse directions

    Jeff Hecht
    Dec. 1, 2004
    Major trends include high powers, coherent beam combination, ultrafast pulses, Q-switching, Raman lasers, and new materials.
    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.
    Fiber Optics

    Carbon coating reduces darkening

    John Wallace
    Dec. 1, 2004
    Optical fibers are useful in "down-hole" energy applications (which include oil, gas, and geothermal wells), serving either as data conduits or sensors.
    Th 165075
    Software

    THREE-DIMENSIONAL IMAGING: Laser scanner helps Olympic win

    Bridget Marx
    Dec. 1, 2004
    In the sport of track cycling, medals are often decided by time differences of a small fraction of a second.
    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.
    Detectors & Imaging

    Display technology spawns laser camera

    Dec. 1, 2004
    An innovative imaging platform has been developed that uses scanned beams of light and is in effect a versatile laser camera.
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    Research

    Diode lasers and LEDs make

    Dec. 1, 2004
    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...
    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).
    Research

    PHOTONIC INTEGRATED CIRCUITS: ARROW principle yields fluid-core waveguides

    Hassaun A. Jones-Bey
    Dec. 1, 2004
    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,...
    Th 165054
    Research

    Nanophotonics: Near-field optics yield nanoscale motion sensor

    Hassaun A. Jones-Bey
    Dec. 1, 2004
    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...
    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].
    Detectors & Imaging

    Academia-industry collaboration feeds exponential growth curve

    Hassaun A. Jones-Bey
    Dec. 1, 2004
    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...
    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.
    Optics

    Small catadioptric objectives extend microscopy into the deep-UV

    Dec. 1, 2004
    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...
    Th 165114
    Optics

    Irregularly figured plates correct wavefront errors

    Dec. 1, 2004
    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...