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  • Volume 55, Issue 09
  • Volume 55, Issue 09

    (Image credit: The Hong Kong Polytechnic University)
    A schematic (a) shows the accelerometer based on a Sagnac interferometer that uses a polarization-maintaining photonic crystal fiber (PM-PCF) sandwiched between a flat substrate and stainless-steel mass. The measured interference spectrum (b) for the 0.35 m link of fiber translates vibration force to parameters that indicate structural health of an affected structure with high sensitivity over a broad frequency range.
    A schematic (a) shows the accelerometer based on a Sagnac interferometer that uses a polarization-maintaining photonic crystal fiber (PM-PCF) sandwiched between a flat substrate and stainless-steel mass. The measured interference spectrum (b) for the 0.35 m link of fiber translates vibration force to parameters that indicate structural health of an affected structure with high sensitivity over a broad frequency range.
    A schematic (a) shows the accelerometer based on a Sagnac interferometer that uses a polarization-maintaining photonic crystal fiber (PM-PCF) sandwiched between a flat substrate and stainless-steel mass. The measured interference spectrum (b) for the 0.35 m link of fiber translates vibration force to parameters that indicate structural health of an affected structure with high sensitivity over a broad frequency range.
    A schematic (a) shows the accelerometer based on a Sagnac interferometer that uses a polarization-maintaining photonic crystal fiber (PM-PCF) sandwiched between a flat substrate and stainless-steel mass. The measured interference spectrum (b) for the 0.35 m link of fiber translates vibration force to parameters that indicate structural health of an affected structure with high sensitivity over a broad frequency range.
    A schematic (a) shows the accelerometer based on a Sagnac interferometer that uses a polarization-maintaining photonic crystal fiber (PM-PCF) sandwiched between a flat substrate and stainless-steel mass. The measured interference spectrum (b) for the 0.35 m link of fiber translates vibration force to parameters that indicate structural health of an affected structure with high sensitivity over a broad frequency range.
    Fiber Optics

    Fiber-optic Sensing: PM-PCF accelerometer has larger frequency range for railway structural health monitoring

    Sept. 1, 2019
    A polarization-maintaining photonic-crystal fiber in a Sagnac interferometer-based accelerometer configuration improves over fiber Bragg grating-based sensors for railway structural...
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    Software

    Fermat paths encode shape of NLOS hidden objects

    Sept. 1, 2019
    By using Fermat’s principle, which states that light takes the path it can traverse in the shortest time, the physical shape of a non-line-of-sight (NLOS) object can be reconstructed...
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    Detectors & Imaging

    Room-temperature low-excess-noise APDs are InP-compatible for lidar applications

    Sept. 1, 2019
    To develop avalanche photodiodes with both high sensitivity and high speed, special alloys lattice-matched to indium phosphide enable telecom-wavelength APDs fast enough to meet...
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    Optics

    Multi-order diffractive optical elements could lead to extremely light space telescopes

    Sept. 1, 2019
    University of Arizona Project Nautilus aims to create a space telescope that can survey transiting exo-earths for biosignatures 1000 light years away.
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    Detectors & Imaging

    Antimonide-based SAM-APDs make sensitive gamma-ray detectors

    Sept. 1, 2019
    Using carefully grown GaSb/AlAsSb heterostructures that act as separate absorption and avalanche layers, gamma rays are easily absorbed and multiplied with high signal-to-noise...

    More content from Volume 55, Issue 09

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    Commentary

    Notes from Optics + Photonics

    Sept. 1, 2019
    Editor in Chief John Lewis introduces Laser Focus World’s September 2019 issue, which includes trends in photonics technologies, applications, and markets.
    FIGURE 1. A flowchart shows the point-by-point design method used to create imaging optics systems from both freeform and planar phase elements.
    FIGURE 1. A flowchart shows the point-by-point design method used to create imaging optics systems from both freeform and planar phase elements.
    FIGURE 1. A flowchart shows the point-by-point design method used to create imaging optics systems from both freeform and planar phase elements.
    FIGURE 1. A flowchart shows the point-by-point design method used to create imaging optics systems from both freeform and planar phase elements.
    FIGURE 1. A flowchart shows the point-by-point design method used to create imaging optics systems from both freeform and planar phase elements.
    Optics

    Imaging Optics: Freeform and planar phase elements combine for better imaging optics

    Sept. 1, 2019
    Using an iterative process that begins with simple geometric planes, freeform surfaces combine with flat phase elements to create compact, lightweight, easily aligned optical ...
    FIGURE 1. The new diode laser can emit more than 400 W; however, its point of operation is chosen to be about 275 W to achieve maximum conversion efficiency.
    FIGURE 1. The new diode laser can emit more than 400 W; however, its point of operation is chosen to be about 275 W to achieve maximum conversion efficiency.
    FIGURE 1. The new diode laser can emit more than 400 W; however, its point of operation is chosen to be about 275 W to achieve maximum conversion efficiency.
    FIGURE 1. The new diode laser can emit more than 400 W; however, its point of operation is chosen to be about 275 W to achieve maximum conversion efficiency.
    FIGURE 1. The new diode laser can emit more than 400 W; however, its point of operation is chosen to be about 275 W to achieve maximum conversion efficiency.
    Lasers & Sources

    High-power Laser Diodes: Diode-laser enhancements boost efficiency and reliability

    Sept. 1, 2019
    Passively cooled high-power laser diodes with nonsoldered joints and new cooling scheme show high reliability under hard-pulsed and continuous-wave operation.
    FIGURE 1. In a Fizeau interferometer, the reflected beam from the reference surface and the reflection from the test surface combine and both reverse their direction, passing through the same optics on their way to the camera.
    FIGURE 1. In a Fizeau interferometer, the reflected beam from the reference surface and the reflection from the test surface combine and both reverse their direction, passing through the same optics on their way to the camera.
    FIGURE 1. In a Fizeau interferometer, the reflected beam from the reference surface and the reflection from the test surface combine and both reverse their direction, passing through the same optics on their way to the camera.
    FIGURE 1. In a Fizeau interferometer, the reflected beam from the reference surface and the reflection from the test surface combine and both reverse their direction, passing through the same optics on their way to the camera.
    FIGURE 1. In a Fizeau interferometer, the reflected beam from the reference surface and the reflection from the test surface combine and both reverse their direction, passing through the same optics on their way to the camera.
    Test & Measurement

    Interferometry: Tradeoffs in fixed vs. continuous-zoom interferometry factor into optics test optimization

    Sept. 1, 2019
    Digital-, discrete-, and continuous-zoom configurations can optimize testing of large and small optics with modern interferometers; however, each method has tradeoffs that users...
    This Cell Atlas diagram allows interactive investigation, and it’s backed by a database for exploring details of individual genes and proteins, as well as systematically analyzing transcriptomes and proteomes in broader contexts. (See https://www.proteinatlas.org/about/licence)
    This Cell Atlas diagram allows interactive investigation, and it’s backed by a database for exploring details of individual genes and proteins, as well as systematically analyzing transcriptomes and proteomes in broader contexts. (See https://www.proteinatlas.org/about/licence)
    This Cell Atlas diagram allows interactive investigation, and it’s backed by a database for exploring details of individual genes and proteins, as well as systematically analyzing transcriptomes and proteomes in broader contexts. (See https://www.proteinatlas.org/about/licence)
    This Cell Atlas diagram allows interactive investigation, and it’s backed by a database for exploring details of individual genes and proteins, as well as systematically analyzing transcriptomes and proteomes in broader contexts. (See https://www.proteinatlas.org/about/licence)
    This Cell Atlas diagram allows interactive investigation, and it’s backed by a database for exploring details of individual genes and proteins, as well as systematically analyzing transcriptomes and proteomes in broader contexts. (See https://www.proteinatlas.org/about/licence)
    Detectors & Imaging

    High-resolution Imaging: AI opens a new era in scientific imaging

    Sept. 1, 2019
    Today’s game-changers in optical microscopy are not the usual suspects.
    (Courtesy of Synopsys)
    FIGURE 1. These freeform optics were designed in LightTools (a). The software can help identify manufacturing tolerances for tailored surfaces used in freeform optics for illumination. Head models are created from image data using Synopsys Simpleware software (b). Simpleware can be used in conjunction with LightTools to run detailed optical scenarios in 3D anatomical models for biomedical applications.
    FIGURE 1. These freeform optics were designed in LightTools (a). The software can help identify manufacturing tolerances for tailored surfaces used in freeform optics for illumination. Head models are created from image data using Synopsys Simpleware software (b). Simpleware can be used in conjunction with LightTools to run detailed optical scenarios in 3D anatomical models for biomedical applications.
    FIGURE 1. These freeform optics were designed in LightTools (a). The software can help identify manufacturing tolerances for tailored surfaces used in freeform optics for illumination. Head models are created from image data using Synopsys Simpleware software (b). Simpleware can be used in conjunction with LightTools to run detailed optical scenarios in 3D anatomical models for biomedical applications.
    FIGURE 1. These freeform optics were designed in LightTools (a). The software can help identify manufacturing tolerances for tailored surfaces used in freeform optics for illumination. Head models are created from image data using Synopsys Simpleware software (b). Simpleware can be used in conjunction with LightTools to run detailed optical scenarios in 3D anatomical models for biomedical applications.
    FIGURE 1. These freeform optics were designed in LightTools (a). The software can help identify manufacturing tolerances for tailored surfaces used in freeform optics for illumination. Head models are created from image data using Synopsys Simpleware software (b). Simpleware can be used in conjunction with LightTools to run detailed optical scenarios in 3D anatomical models for biomedical applications.
    Software

    Illumination Optical-design Software: Illumination-design software optimizes complex geometries

    Sept. 1, 2019
    In its many different forms, illumination-design software models and optimizes complex optics and the illumination fields that they produce.
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    Commentary

    Business Forum: Sensing changes at the Marketplace Seminar

    Sept. 1, 2019
    Changing photonics markets and increasing economic uncertainty frame discussions at the Lasers & Photonics Marketplace Seminar.
    Test & Measurement

    IceCube ice anisotropy could be due to birefringent polycrystals

    Sept. 1, 2019
    A twofold difference in ice attenuation in perpendicular directions in the IceCube experiment could be explained by a birefringent structure of the microcrystals in the ice.
    A photonic crystal (PhC) with a heterostructure cavity achieves double resonance even though it has only one bandgap, not two; the second resonance is provided by a “bound state in the continuum” (BIC). The heterostructure cavity includes a core, a transition region, and an outer region (delineated here by dotted lines). The relevant resonant mode is confined to the core region. Creating such a PhC out of a nonlinear optical material allows PhC-based optical frequency doubling for the first time.
    A photonic crystal (PhC) with a heterostructure cavity achieves double resonance even though it has only one bandgap, not two; the second resonance is provided by a “bound state in the continuum” (BIC). The heterostructure cavity includes a core, a transition region, and an outer region (delineated here by dotted lines). The relevant resonant mode is confined to the core region. Creating such a PhC out of a nonlinear optical material allows PhC-based optical frequency doubling for the first time.
    A photonic crystal (PhC) with a heterostructure cavity achieves double resonance even though it has only one bandgap, not two; the second resonance is provided by a “bound state in the continuum” (BIC). The heterostructure cavity includes a core, a transition region, and an outer region (delineated here by dotted lines). The relevant resonant mode is confined to the core region. Creating such a PhC out of a nonlinear optical material allows PhC-based optical frequency doubling for the first time.
    A photonic crystal (PhC) with a heterostructure cavity achieves double resonance even though it has only one bandgap, not two; the second resonance is provided by a “bound state in the continuum” (BIC). The heterostructure cavity includes a core, a transition region, and an outer region (delineated here by dotted lines). The relevant resonant mode is confined to the core region. Creating such a PhC out of a nonlinear optical material allows PhC-based optical frequency doubling for the first time.
    A photonic crystal (PhC) with a heterostructure cavity achieves double resonance even though it has only one bandgap, not two; the second resonance is provided by a “bound state in the continuum” (BIC). The heterostructure cavity includes a core, a transition region, and an outer region (delineated here by dotted lines). The relevant resonant mode is confined to the core region. Creating such a PhC out of a nonlinear optical material allows PhC-based optical frequency doubling for the first time.
    Optics

    Nonlinear Optics: Light-trapping, frequency-doubling photonic crystal is first of its kind

    Sept. 1, 2019
    The photonic crystal traps the fundamental frequency via a conventional bandgap and the doubled frequency using a “bound state in the continuum.”
    Biological nanomaterials with fluorescence properties, DNA-stabilized metal quantum clusters promise to enable quick and reliable biosensors.
    Biological nanomaterials with fluorescence properties, DNA-stabilized metal quantum clusters promise to enable quick and reliable biosensors.
    Biological nanomaterials with fluorescence properties, DNA-stabilized metal quantum clusters promise to enable quick and reliable biosensors.
    Biological nanomaterials with fluorescence properties, DNA-stabilized metal quantum clusters promise to enable quick and reliable biosensors.
    Biological nanomaterials with fluorescence properties, DNA-stabilized metal quantum clusters promise to enable quick and reliable biosensors.
    Research

    Biosensors: Quantum technology promises better biosensors

    Sept. 1, 2019
    Applying quantum technology to biosensing, for example, using DNA-stabilized metal ‘quantum clusters,’ will help extend the capabilities of modern optical biosensing.
    FIGURE 1. The rubidium titanyl phosphate (RTP) Q-switch is assembled in a thermally compensated double-crystal configuration in which two matched crystals are placed in line with the propagation axis (x or y) with one crystal rotated by 90° with respect to the other.
    FIGURE 1. The rubidium titanyl phosphate (RTP) Q-switch is assembled in a thermally compensated double-crystal configuration in which two matched crystals are placed in line with the propagation axis (x or y) with one crystal rotated by 90° with respect to the other.
    FIGURE 1. The rubidium titanyl phosphate (RTP) Q-switch is assembled in a thermally compensated double-crystal configuration in which two matched crystals are placed in line with the propagation axis (x or y) with one crystal rotated by 90° with respect to the other.
    FIGURE 1. The rubidium titanyl phosphate (RTP) Q-switch is assembled in a thermally compensated double-crystal configuration in which two matched crystals are placed in line with the propagation axis (x or y) with one crystal rotated by 90° with respect to the other.
    FIGURE 1. The rubidium titanyl phosphate (RTP) Q-switch is assembled in a thermally compensated double-crystal configuration in which two matched crystals are placed in line with the propagation axis (x or y) with one crystal rotated by 90° with respect to the other.
    Test & Measurement

    Optical Materials: RTP optical crystal helps boost performance of LIGO

    Sept. 1, 2019
    Upgrading the Laser Interferometer Gravitational-Wave Observatory (LIGO) included the addition of a rubidium titanyl phosphate (RTP) Q-switch to handle high optical powers.