• Back Issues >
  • Laser Focus World >
  • Volume 53, Issue 11
  • Volume 53, Issue 11

    More content from Volume 53, Issue 11

    FIGURE 1. Beam divergence depends on the ratio of the wavelength and aperture diameter of the emitting antenna (radar) or lens (lidar). This ratio is larger for radar producing larger beam divergence and, therefore, smaller angular resolution. In the figure, the radar (black) would not be able to differentiate between the two cars, while lidar (red) would.
    Lidar vs. competing sensor technologies (camera, radar, and ultrasonic) reinforces the need for sensor fusion, as well as careful selection of photodetectors, light sources, and...
    Nov. 9, 2017
    (Courtesy of OSRAM Opto Semiconductors)
    FIGURE 1. These unmounted pump laser-diode chips made by OSRAM Opto Semiconductors include high-power quasi-continuous-wave (QCW) bars (top left), low-fill-factor CW bars (top right), high-power CW bars (bottom left), and tailored mini-bars (bottom right).
    Laser diodes are efficient, narrowband, bright, and long-life, making them the ideal laser-pump source, and can be made to produce extremely high optical powers.
    Nov. 9, 2017
    (Courtesy of NPOI and MROI)
    IARPA is soliciting solutions that miniaturize and reduce cost for the ground-based interferometric detection of geosynchronous earth-orbiting (GEO) satellites. Shown here is the existing Navy Prototype Optical Interferometer (NPOI; a) and the under-construction Magdalena Ridge Observatory Interferometer (MROI; b)—sites that provide the framework for a less-costly, smaller system.
    The Amon-Hen program targets an interferometer system cost of less than $25 million in a footprint smaller than existing ground-based interferometry sites.
    Nov. 9, 2017
    Spatial and spectral (x × y pixels, and wavenumber, or w, respectively) data in each imaging plane combine to produce a volumetric hyperspectral dataset (z × x, with z equaling the sum of y planes). Unfolding the dataset produces a matrix (D=M × w, with M equaling z × x) useful for spectral unmixing analysis: D is unmixed into two matrices, C and ST, based on the quantity (N) of 'pure' components (in this example, N=4). The C matrix includes relative abundance values for the 'pure' components of each voxel in an M × N grid—in which every column corresponds to a single component. The ST matrix is an N × w grid that includes a 'pure' component spectrum in each row. Each C column provides the spatial data necessary to reconstruct the 3D architecture of every component, by refolding to its original x × y × z; and each voxel includes the reconstructed component's concentration profile. Quantification is enabled by comparing the number of voxels within an isosurface (the 3D analog of an isoline; e.g., cells A and B).
    The need for quantitative, nondestructive tools led a team of scientists to develop quantitative volumetric Raman imaging, a novel, label-free method of imaging multiple biomolecules...
    Nov. 9, 2017
    Approaching the desired Rec. 2020 color gamut standard, RGB laser projectors are capable of reproducing more colors than the typical Rec. 709 or hero DCI P3 standard achieved by an LED cinema screen.
    Christie sheds light on the technical comparison between RGB laser projection and LED modules when used as the light engines for cinema-scale display applications.
    Nov. 9, 2017
    (Courtesy of the Department of Electronic and Computer Engineering, HKUST/Peter Allen)
    A schematic shows the electrically pumped quantum-dot microring laser created at HKUST and UCSB; periodic quantum-dot-in-a-well layers can be seen at the centers of the lasers.
    A team of researchers has created record-small electrically pumped microlasers epitaxially grown on industry-standard (001) silicon substrates.
    Nov. 9, 2017
    Content Dam Lfw Print Articles 2017 11 1711lfw Nb F5
    After years of development, KMLabs has commercially introduced the first titanium:sapphire (Ti:sapphire) ultrafast laser oscillator directly pumped with blue-emitting laser diodes...
    Nov. 9, 2017
    Content Dam Lfw Print Articles 2017 11 1711lfw Nb F4
    A broadband, compact, and low-cost diffuser-based wavefront sensor works by simply placing a thin diffuser near a camera to allow sensing of the local wavefront gradient by measuring...
    Nov. 9, 2017
    A research team is beginning the development of a laser that will have a much higher peak power of 100 PW.
    Nov. 9, 2017
    Content Dam Lfw Print Articles 2017 11 1711lfw Nb F3
    The instrument is suited to water-quality research and monitoring, wine-constituent analysis, protein purity, and vaccine quality-assurance applications.
    Nov. 9, 2017
    Content Dam Lfw Print Articles 2017 11 1711lfw Nb 1
    A miniaturized Stirling and Joule-Thomson (J-T) cooling platform, which was the prototype design for the cooler launched in 2009 onboard an Ariane 5 rocket as part of the Planck...
    Nov. 9, 2017
    Conard Holton2
    No tradeshow or conference truly captures the photonics world, even SPIE Photonics West and LASER World of Photonics.
    Nov. 9, 2017