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    • Volume 55, Issue 05

    More content from Volume 55, Issue 05

    FIGURE 1. A simplified schematic shows the main elements of a weathering testing chamber.
    A clever spin on sputtered coating technology provides a more accurate simulation of sunlight.
    May 1, 2019
    (Courtesy of Hamamatsu)
    FIGURE 1. As seen in this schematic, a confocal laser scanning microscope includes two PMTs for light-sensing.
    Based on tried-and-true tube technology, PMTs still have, for many applications, low-light performance unmatched by other technologies.
    May 1, 2019
    (Courtesy of Cincinnati Children’s Hospital Medical Center)
    Light-sensitive opsin proteins, which researchers discovered in the retinal ganglia nerve fibers of the neonatal mouse eye, will help them investigate light-based therapies to prevent or treat eye diseases.
    A new technique may enable light-based treatment for eye diseases including severe near-sightedness and for helping premature infants avoid later vision problems.
    May 1, 2019
    (Image credit: Takao Aoki/Waseda University)
    In the coupled-cavity QED system, cavities 1 and 2 of length L1 and L2 (with coupling rates v1 and v2 as well as atom-cavity coupling rates of g1 and g2, respectively) couple to a length of fiber Lf; measurements are made from left to right using a probe beam.
    An all-optical-fiber coupled-cavities quantum electrodynamics (QED) system demonstrates a reversible interaction between atoms and photons separated by 2 m of fiber—an important...
    May 1, 2019
    (Courtesy of Zongfu Yu)
    This compact and low-cost spectrometer could help turn ordinary cell phones into advanced analytical tools; at the center of the device, a 210-µm-square photonic-crystal slab sits atop a camera sensor.
    A spectrometer based on photonic-crystal slabs with ‘random’ spectral responses can be fabricated using standard CMOS technology.
    May 1, 2019
    (Image credit: NASA and Discovery Semiconductors)
    An ultrafast InGaAs dual-depletion region photodiode (a) with a radiation-hardened design and spanning 1060 to 1650 nm was incorporated into a fiber-coupled 16.8 GHz module (b) that survived 18 months on the ISS as part of the MISSE 7 mission launched on the Space Shuttle Atlantis and returning on the Space Shuttle Endeavor.
    Dual-depletion region InGaAs photodiodes have a radiation-hardened architecture that qualifies them for the rigors of lidar, communications, and referencing systems in space-based...
    May 1, 2019
    A laser-based instrument for remote detection of radioactivity uses a mid-IR laser to induce avalanche breakdown in air, but only when radioactivity is present, and a probe beam to detect the breakdown. In the setup, a 3.9 µm pulsed pump laser beam copropagates with a 1.45 µm chirped pulsed probe laser beam (both produced by an optical parametric amplifier, and thus proportional to each other in power), passing through beamsplitter 1 to send part of the probe light to reference photodetector 1. Driven by the pump light focused by lens 1, ionizing radiation from a polonium source seeds avalanche ionization (yellow spark). Speed of breakdown is proportional to radioactivity density. The increasing plasma density blocks the chirped probe light after the breakdown time (in this version, speed of breakdown is proportional to radioactivity density), resulting in the detection, measured by a spectrometer.
    A laser-based instrument measures radioactivity at a distance and is thus potentially useful for security at ports of entry.
    May 1, 2019
    (Image credit: National Institute for Laser, Plasma and Radiation Physics)
    A block diagram shows the experimental setup for a LI system (a); the physical configuration is shown for a gasoline engine equipped with the LI system (b).
    Laser-based ignition systems for internal combustion engines continue to advance; laser miniaturization and beam characteristics continue to improve towards commercial implementation...
    May 1, 2019
    With LED pumping of only 14 W/cm2 peak power, an acousto-optically Q-switched Nd:YLF laser produces pulses with duration of 452 ns and energy of 10.6 μJ.
    May 1, 2019
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    Fabrication of aspheric microlens arrays through direct cutting or grinding methods can be expensive and limited to small batches; a new off-axis spindle grinding method forms...
    May 1, 2019
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    A circuit analog of time-resolved microwave reflectance using an RF-concentrating resonator amplifies the response to optical excitation of a small volume of optoelectronic material...
    May 1, 2019
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    Matching two QKD entangled photons’ wavelengths to the right parts of the fiber dispersion curve for two fiber routes allows both photons to arrive simultaneously.
    May 1, 2019
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    By illuminating a mixture of polymers with different wavelengths of light in a pre-determined spatial and temporal pattern, standard vat polymerization can build a multimaterial...
    May 1, 2019
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    Editor in Chief John Lewis celebrates the life of Andrew Charles Wilson, his impact on machine vision and imaging, and introduces Laser Focus World’s May 2019 issue, which includes...
    May 1, 2019