• Back Issues >
  • Laser Focus World >
  • Volume 47, Issue 6
  • Volume 47, Issue 6

    Optics

    IN MY VIEW: How (not) to buy an (electronic) book

    June 1, 2011
    Time was when the buying and reading of a new book was quite simple. If you read a promising review of a recently published book, a quick phone call to your local bookseller would...
    A magnetic field creates transitions between Zeeman sublevels in a 229Th nucleus, some of which can lead to a vacuum-ultraviolet nuclear laser—a precursor to a gamma-ray laser (Jπ = 5/2 is the ground state; Jπ = 3/2 is the first excited level; m are the sublevels).
    A magnetic field creates transitions between Zeeman sublevels in a 229Th nucleus, some of which can lead to a vacuum-ultraviolet nuclear laser—a precursor to a gamma-ray laser (Jπ = 5/2 is the ground state; Jπ = 3/2 is the first excited level; m are the sublevels).
    A magnetic field creates transitions between Zeeman sublevels in a 229Th nucleus, some of which can lead to a vacuum-ultraviolet nuclear laser—a precursor to a gamma-ray laser (Jπ = 5/2 is the ground state; Jπ = 3/2 is the first excited level; m are the sublevels).
    A magnetic field creates transitions between Zeeman sublevels in a 229Th nucleus, some of which can lead to a vacuum-ultraviolet nuclear laser—a precursor to a gamma-ray laser (Jπ = 5/2 is the ground state; Jπ = 3/2 is the first excited level; m are the sublevels).
    A magnetic field creates transitions between Zeeman sublevels in a 229Th nucleus, some of which can lead to a vacuum-ultraviolet nuclear laser—a precursor to a gamma-ray laser (Jπ = 5/2 is the ground state; Jπ = 3/2 is the first excited level; m are the sublevels).
    Research

    LASER PHYSICS: Nuclear-laser idea hints at gamma-ray laser future

    June 1, 2011
    The "gamma-ray laser"—a much discussed but never before realized construct of nuclear physics—looks more plausible thanks to a new theoretical study.
    (Courtesy of Awaiba GmbH)
    Through-silicon-via (TSV) technology enables low-cost CMOS cameras smaller than a match head.
    Through-silicon-via (TSV) technology enables low-cost CMOS cameras smaller than a match head.
    Through-silicon-via (TSV) technology enables low-cost CMOS cameras smaller than a match head.
    Through-silicon-via (TSV) technology enables low-cost CMOS cameras smaller than a match head.
    Through-silicon-via (TSV) technology enables low-cost CMOS cameras smaller than a match head.
    Detectors & Imaging

    MINIATURE CAMERAS: Through-silicon vias make microcameras even smaller

    June 1, 2011
    Building on earlier work that described breakthrough wafer-level-packaging developments related to miniature CMOS imagers with 1.7 µm pixel pitch, researchers at the Fraunhofer...
    (Courtesy of the University of Michigan)
    The trajectory of electron motion (away from its nucleus at x = y = z = 0) in a dielectric material illuminated by an incident electric field strength of (a) 1 V/m is compared to illumination with a strength of (b) 108 V/m. For the low-intensity light field, the x and z axes differ by nine orders of magnitude and the electron moves along the electric field x. At a higher light intensity, motion shifts to z, the direction of light propagation, and is much larger than expected.
    The trajectory of electron motion (away from its nucleus at x = y = z = 0) in a dielectric material illuminated by an incident electric field strength of (a) 1 V/m is compared to illumination with a strength of (b) 108 V/m. For the low-intensity light field, the x and z axes differ by nine orders of magnitude and the electron moves along the electric field x. At a higher light intensity, motion shifts to z, the direction of light propagation, and is much larger than expected.
    The trajectory of electron motion (away from its nucleus at x = y = z = 0) in a dielectric material illuminated by an incident electric field strength of (a) 1 V/m is compared to illumination with a strength of (b) 108 V/m. For the low-intensity light field, the x and z axes differ by nine orders of magnitude and the electron moves along the electric field x. At a higher light intensity, motion shifts to z, the direction of light propagation, and is much larger than expected.
    The trajectory of electron motion (away from its nucleus at x = y = z = 0) in a dielectric material illuminated by an incident electric field strength of (a) 1 V/m is compared to illumination with a strength of (b) 108 V/m. For the low-intensity light field, the x and z axes differ by nine orders of magnitude and the electron moves along the electric field x. At a higher light intensity, motion shifts to z, the direction of light propagation, and is much larger than expected.
    The trajectory of electron motion (away from its nucleus at x = y = z = 0) in a dielectric material illuminated by an incident electric field strength of (a) 1 V/m is compared to illumination with a strength of (b) 108 V/m. For the low-intensity light field, the x and z axes differ by nine orders of magnitude and the electron moves along the electric field x. At a higher light intensity, motion shifts to z, the direction of light propagation, and is much larger than expected.
    Research

    OPTOELECTRONIC THEORY: Optical capacitor leverages light’s magnetic field

    June 1, 2011
    Imagine converting the Sun's energy to electricity without the need for expensive semiconductor materials or the usual absorption-exciton-drift-current conversion steps. This ...
    Cross-correlation traces show the difference in pulse delay for a 450 fs Stokes pulse passing through a 5 cm polymer waveguide (a). Delay time of the Stokes pulse is shown (b) for two values of the input Stokes bandwidth, 5 nm (blue) and 8 nm (purple).
    Cross-correlation traces show the difference in pulse delay for a 450 fs Stokes pulse passing through a 5 cm polymer waveguide (a). Delay time of the Stokes pulse is shown (b) for two values of the input Stokes bandwidth, 5 nm (blue) and 8 nm (purple).
    Cross-correlation traces show the difference in pulse delay for a 450 fs Stokes pulse passing through a 5 cm polymer waveguide (a). Delay time of the Stokes pulse is shown (b) for two values of the input Stokes bandwidth, 5 nm (blue) and 8 nm (purple).
    Cross-correlation traces show the difference in pulse delay for a 450 fs Stokes pulse passing through a 5 cm polymer waveguide (a). Delay time of the Stokes pulse is shown (b) for two values of the input Stokes bandwidth, 5 nm (blue) and 8 nm (purple).
    Cross-correlation traces show the difference in pulse delay for a 450 fs Stokes pulse passing through a 5 cm polymer waveguide (a). Delay time of the Stokes pulse is shown (b) for two values of the input Stokes bandwidth, 5 nm (blue) and 8 nm (purple).
    Research

    INTEGRATED PHOTONICS: Slow light is created on a printed-circuit board

    June 1, 2011
    The generation of "slow light" (in which the group velocity of light in a material is slowed down substantially due to a specially tailored dispersion profile) is potentially ...

    More content from Volume 47, Issue 6

    (Courtesy of OFS Denmark)
    The refractive index profile is shown for a germanium oxide depressed-cladding few-moded fiber (a) designed for optical-dispersion compensation in coherent communications networks. Its effective area and dispersion (b) exceed those for existing fiber designs.
    The refractive index profile is shown for a germanium oxide depressed-cladding few-moded fiber (a) designed for optical-dispersion compensation in coherent communications networks. Its effective area and dispersion (b) exceed those for existing fiber designs.
    The refractive index profile is shown for a germanium oxide depressed-cladding few-moded fiber (a) designed for optical-dispersion compensation in coherent communications networks. Its effective area and dispersion (b) exceed those for existing fiber designs.
    The refractive index profile is shown for a germanium oxide depressed-cladding few-moded fiber (a) designed for optical-dispersion compensation in coherent communications networks. Its effective area and dispersion (b) exceed those for existing fiber designs.
    The refractive index profile is shown for a germanium oxide depressed-cladding few-moded fiber (a) designed for optical-dispersion compensation in coherent communications networks. Its effective area and dispersion (b) exceed those for existing fiber designs.
    Research

    FEW-MODED FIBER: Dispersion-compensating fibers show 4X+ improvement

    June 1, 2011
    Scientists at OFS Denmark (Brøndby, Denmark) and OFS Labs (Somerset, NJ) have developed a dispersion-compensating optical fiber with a factor of 5.0 improvement in figure of merit...
    1106breaks Fig2a
    1106breaks Fig2a
    1106breaks Fig2a
    1106breaks Fig2a
    1106breaks Fig2a
    Research

    Silver and gold beetles inspire new optical materials

    June 1, 2011
    The secret to the shimmering brilliance of two beetles that shine naturally with silver and gold colors has been unlocked by researchers at Universidad de Costa Rica (San José...
    Pennwell web 350 315
    Pennwell web 350 315
    Pennwell web 350 315
    Pennwell web 350 315
    Pennwell web 350 315
    Research

    Quantum-dot PC laser has lowest-threshold emission

    June 1, 2011
    For applications such as on-chip and intrachip optical communications, electrically pumped lasers with compact size, low power dissipation, and low-threshold operation are needed...
    Detectors & Imaging

    GeSn photodetector spans all telecom wavebands

    June 1, 2011
    Germanium (Ge)-on-silicon photodetectors operate successfully in the telecommunications wavelength ranges centered at 1310 nm and 1550 nm (the C- and L-bands), respectively; however...
    Optics

    PV module concentrates sunlight, lets light through for windows

    June 1, 2011
    A see-through photovoltaic (PV) module for window-integrated use developed at the Nagaoka University of Technology (Niigata, Japan) contains a low-concentration prism concentrator...
    Fiber Optics

    Enhancement cavity creates green light simply from IR fiber laser

    June 1, 2011
    Concocting a green-light-emitting fiber laser has meant taking the output of an IR-emitting fiber laser (for example, around 1060 nm) and frequency doubling it. Researchers at...
    Fiber Optics

    Nanosecond laser pulses efficiently drill holes in metal

    June 1, 2011
    Percussion drilling with nanosecond laser-pulse bursts, instead of single nanosecond pulses, has advantages for metal machining, according to researchers from Multiwave Photonics...
    FIGURE 1. The output pulse of a directly modulated laser diode shown in (a) can be divided into two parts: the initial overshoot region (c) and the primary region (d) by spectral filtering (b).
    FIGURE 1. The output pulse of a directly modulated laser diode shown in (a) can be divided into two parts: the initial overshoot region (c) and the primary region (d) by spectral filtering (b).
    FIGURE 1. The output pulse of a directly modulated laser diode shown in (a) can be divided into two parts: the initial overshoot region (c) and the primary region (d) by spectral filtering (b).
    FIGURE 1. The output pulse of a directly modulated laser diode shown in (a) can be divided into two parts: the initial overshoot region (c) and the primary region (d) by spectral filtering (b).
    FIGURE 1. The output pulse of a directly modulated laser diode shown in (a) can be divided into two parts: the initial overshoot region (c) and the primary region (d) by spectral filtering (b).
    Fiber Optics

    FIBER LASERS: Pulsed fiber lasers reach 50 kW peak power at < 100 ps pulse duration

    May 19, 2011
    Competing nonlinear processes have limited pulsed fiber lasers to modest peak powers, restricting application possibilities. But a new pulsed laser overcomes this barrier through...