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  • Volume 57, Issue 04

    • Volume 57, Issue 04

    More content from Volume 57, Issue 04

    Accelerating a small chemical specimen to relativistic speeds slows down its “internal clock,” enabling higher temporal resolution for ultrafast studies.
    April 21, 2021
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    Confirmed by experiment, calculations show how deep light goes into a DBR mirror before it reflects; this is relevant for determining microcavity lengths.
    April 21, 2021
    In a single-mode optical fiber with a 10-μm-diameter core, a high-refractive-index rod is placed a distance S away in the cladding; the rod itself supports a mode, in addition to the mode supported by the core (a). The idea is for the rod to couple resonantly to the core, drawing light in certain spectral regions away from the core and absorbing it, thus serving as a spectral filter. The width of the peak bandwidth narrowed as the rod was moved farther from the core (b).
    A single-mode silica fiber has a high-refractive-index rod placed in the cladding that resonates with the core, absorbing light at certain wavelengths.
    April 21, 2021
    A resonance curve from two coupled microring resonators producing a microcomb is fit with a curve that models a resonance doublet.
    Using a laser with a milliwatts-level output, two linearly coupled microresonators produce a microcomb potentially widely useful in spectroscopy, communications, and other applications...
    April 21, 2021
    (Image credit: SIOM)
    For extreme-ultraviolet (EUV) lithographic systems in which the photomask needs to be optimized to minimize optical-proximity effects, a simultaneous source-mask optimization (SMO) algorithm using a thick-mask model results in more-accurate features printed at the wafer.
    A software algorithm based on social learning particle swarm optimization (SL-PSO) simultaneously optimizes source and mask for extreme-ultraviolet (EUV) lithography.
    April 21, 2021
    (Adapted from J. Knall et al. [1])
    A Yb-doped silica fiber is pumped with light at a wavelength ranging from 1020 to 1070 nm, causing anti-Stokes fluorescence that carries some energy away. Depending on the wavelength, enough energy can be carried away to exceed the amount of energy dumped into the fiber as heat, thus cooling the fiber. As can be seen, the optimum pump wavelength in the experiment was about 1040 nm.
    A ytterbium-doped silica fiber laser pumped with light at 1040 nm loses enough heat via anti-Stokes fluorescence to become athermal.
    April 21, 2021
    (Courtesy of the Catalan Institute of Nanoscience and Nanotechnology)
    A new interferometric sensor has demonstrated the ability to rapidly and accurately detect low levels of pathogenic bacteria in a compact point-of-care device.
    A bimodal waveguide sensor has a waveguide portion biochemically functionalized to bind to a specific target, allowing interferometric sensing of the target.
    April 21, 2021
    FIGURE 1. Schematic of an edge coupler (a) and a grating coupler (b).
    Efficiently linking optical fibers to silicon photonics is crucial to high-volume deployment; a new monolithic 1:1 imaging coupler is compact and suitable for volume fabrication...
    April 21, 2021
    FIGURE 1. Two-dimensional array of micromirrors with three possible angular positions: flat, tilted v degrees anticlockwise, and tilted +v degrees clockwise.
    Compact near-infrared spectrometers based on digital micromirror devices (DMDs) can be lower in cost than diode-array spectrometers while maintaining high stability.
    April 21, 2021
    FIGURE 1. Lasers commonly used for fractional photothermolysis treatment have wavelengths highly absorbed by water and less absorbed by melanin and hemoglobin.
    As a monolithic semiconductor device that converts electrical energy directly into light, the diode laser, when compared with other laser sources for skin rejuvenation, has many...
    April 21, 2021
    FIGURE 1. Schematic of a typical ultrafast fiber-laser oscillator (a); Calmar Laser’s palm-sized Mendocino ultrafast fiber laser offers output wavelengths from 780 to 1560 nm (b).
    Fiber-based ultrafast laser platforms enable medical and industrial applications from cancer diagnosis to terahertz imaging and 3D nanoprinting.
    April 21, 2021
    FIGURE 1. Attenuation of optical fibers made of fluoride glasses, showing a significantly wider transmission window into the mid-IR as compared to silica fibers. Indium fluoride (InF3) glass has a wider transmission window in the mid-IR than zirconium fluoride (ZrF4) glass.
    A commercially available mid-IR supercontinuum source has a broadband output from 1.3 to 4.5 μm, providing orders-of-magnitude higher brightness than thermal IR sources.
    April 21, 2021
    FIGURE 1. Automotive HUD system concept.
    Design of head-up display systems for automotive applications benefits from modern optical design and illumination software.
    April 21, 2021
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    A method of fusing photonic-crystal fiber ends using a heated U-shaped graphite filament produces lensed tips with long working distance and wide bandwidth.
    April 21, 2021
    (Photo 183113861 © Toodlingstudio | Dreamstime.com)
    Dreamstime M 183113861
    They likely will—find out how by viewing the Lasers & Photonics Marketplace Seminar Wrap Up Roundtable Discussion.
    April 2, 2021