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  • Volume 54, Issue 08

    • Volume 54, Issue 08

    (Courtesy of SpectraSensors)
    FIGURE 1. The 2f signal peak-to-valley height provides improved sensitivity and stability.
    Spectroscopy

    Photonics Applied: Atmospheric Sensing: TDLAS atmospheric water vapor sensing improves weather forecasting

    Aug. 1, 2018
    Through aircraft-based meteorological observations, tunable diode laser absorption spectroscopy (TDLAS) techniques are making a global contribution to atmospheric sensing advances...
    FIGURE 1. This figure of the basic principle of fiber Bragg grating (FBG) sensing has been conveyed in numerous published journals and conference proceedings, revealing the beautiful, simple elegance of the technique.
    Fiber Optics

    Fiber-Optic Sensing: Leveraging three decades of fiber Bragg grating sensing technology

    Aug. 1, 2018
    Propelled by three decades of technological development, fiber-Bragg-grating-based optical sensors continue to advance and serve existing and new sensing applications.
    Content Dam Lfw Print Articles 2018 08 1808lfw Qia F1
    Fiber Optics

    Manufacturing Photonics: Challenges for photonics manufacturing in the new data center era

    Aug. 1, 2018
    The high-volume and high-mix nature of manufacturing for hyperscale data centers requires flexible, high speed, and high precision automation to enable just-in-time supply and...
    (Image credit: Sedat Nizamoglu, Koç University)
    In a comparison of luminous efficiency for liquid-state, solid-state, and close-packed QD white LEDs, the liquid-state LED comes out on top with a luminous efficiency of 64 lm/W (a); a liquid-state white LED is filled with red- and green-emitting QD solutions by injecting a QD solution into the assembled LED through the silicone polymeric lens (b).
    Lasers & Sources

    Quantum Dots: Liquid-state quantum dot white LEDs have high luminous efficiency

    John Wallace
    Aug. 1, 2018
    Researchers at Koç University (Istanbul, Turkey) and PSR Arts and Science College (Sivakasi, India) have demonstrated quantum-dot (QD)-based white LEDs that exhibit a record luminous...
    (Image credit: Vladislav Shcheslavskiy)
    This macro-FLIM system provides cellular-level resolution in specimen areas up to 4 cm2 with high molecular specificity.
    Research

    Advanced Imaging/Fluorescence: Macro-FLIM provides molecular specificity with cellular resolution

    Barbara Gefvert
    Aug. 1, 2018
    Having overcome important limitations of fluorescence intensity imaging, fluorescence lifetime imaging (FLIM) and other time-resolved methods are increasingly recognized as beneficial...

    More content from Volume 54, Issue 08

    Eric Proctor, William Parks, Benjamin S. Riggan/U.S. Army Research Laboratory
    Thermal imaging and deep neural networks combine in a thermal-to-visible, nighttime facial recognition system that is interoperable with visible-light-based facial recognition systems.
    Detectors & Imaging

    Thermal Imaging: Software algorithms and thermal imaging combine to recognize faces in the dark

    Gail Overton
    Aug. 1, 2018
    Facial recognition continues to be challenging, but is advancing in large part because of specialized software algorithms that take clues from the surrounding environment for ...
    (Image credit: Jarrahi Research Group/UCLA)
    An optical photodiode made of gold-patched graphene nanostripes operates across a broad range of wavelengths and has a speed of 50 GHz.
    Detectors & Imaging

    Photodiodes: Graphene photodetector has 50 GHz speed and high responsivity from 0.6 to 20 μm

    John Wallace
    Aug. 1, 2018
    Conventional semiconductor photodiode materials (silicon, indium gallium arsenide, mercury cadmium telluride, and so on), while extremely useful in photonics, have sensitivities...
    Content Dam Lfw Print Articles 2018 08 1808lfwcvr
    Optics

    Optical Isolators: The light valve: a rapidly spinning glass sphere isolates light

    Gail Overton
    Aug. 1, 2018
    Optical isolators—components that transmit light in only one direction and block it in another—are crucial for protecting laser sources from back reflections and/or routing or...
    1808 Lfw Nb 2
    Research

    Investigation with a femtosecond fiber laser finds new type of soliton ‘molecule’

    John Wallace
    Aug. 1, 2018
    Only by understanding limitations of plasmonic polariton confinement within materials like graphene can future nanophotonic engineering be improved.
    Content Dam Lfw Print Articles 2018 08 1808lfw Nb F4
    Test & Measurement

    Simple shearing interferometer measures wavefront of femtosecond laser pulses

    John Wallace
    Aug. 1, 2018
    Using an interferometer to characterize the spatial information of a continuous-wave (CW) laser beam can be done straightforwardly using a shearing interferometer, where the test...
    Content Dam Lfw Print Articles 2018 08 1808lfw Nb F3
    Fiber Optics

    Selective transparency enables point-by-point grating writing in photonic crystal fibers

    Gail Overton
    Aug. 1, 2018
    It is widely believed that photonic crystals demonstrate transparency (the ability to transmit light without scattering or diffraction) only when the considered wavelength is ...
    Content Dam Lfw Print Articles 2018 08 1808lfw Nb F1
    Lasers & Sources

    Underwater communication and illumination uses RGB white-light laser source

    Gail Overton
    Aug. 1, 2018
    To date, underwater optical communications using blue or blue-green lasers or LEDs are considered optimal to achieve high bandwidth and high data transmission rate.
    Susan Reiss 720
    Detectors & Imaging

    Business Forum: 2019 U.S. budget could benefit biophotonics

    Susan Reiss
    Aug. 1, 2018
    Congressional negotiations over the FY2019 budget look promising for bio-optics technologies that stretch the edges of discovery for personalized medicine, neuroscience, biosensing...
    Conard Holton2
    Spectroscopy

    A sensitive nature

    Conard Holton
    Aug. 1, 2018
    Light is an invaluable tool for very diverse applications, but none more so than sensing. And sensing with multiple wavelengths takes many forms—for example, tunable diode laser...
    FIGURE 1. The basic principle of a Fabry-Perot interference filter is detailed.
    Detectors & Imaging

    Hyperspectral Imaging: Hyperspectral microscopy serves biological pathology

    Alexandre Fong
    Aug. 1, 2018
    Spectral unmixing and other image processing techniques applied to hyperspectral data reveal subtle color and texture differences not seen in standard microscopy images, improving...
    FIGURE 1. Three-dimensional shape sensing promises to facilitate procedures such as coronary angioplasty with highly accurate GPS-like guidance provided by feedback from the optical fiber, which exhibits strain when bent; this application is enabled by a highly complex optical fiber such as the spun seven-core SM-7C 1500(6.1/125).
    Detectors & Imaging

    Advanced Optics: Advanced fiber optics further biomedicine

    Andy Gillooly
    Aug. 1, 2018
    Leading-edge manufacturing processes have enabled the production of optical fibers robust and flexible enough to address an exciting new range of biomedical applications.
    FIGURE 1. Detector sensitivity vs. wavelength for silicon (Si) and InGaAs photodiodes.
    Lasers & Sources

    How to Choose a Laser: How to choose a laser for Raman spectroscopy

    Elizabeth Illy
    Aug. 1, 2018
    Here, in detail, are the lasers that can be used for Raman spectroscopy and why.
    FIGURE 1. Light propagates clockwise (dashed line) and counterclockwise (solid line) along the edge of a circle, which is also rotating.
    Software

    Modeling Software: Understanding the Sagnac effect through ray optics simulation

    Christopher Boucher
    Aug. 1, 2018
    Rotation effects on laser ring gyroscopes and other rotating optical devices can now be straightforwardly modeled.