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  • Volume 54, Issue 12

    • Volume 54, Issue 12

    The measured SHG conversion efficiency vs. pump wavelength is shown for two waveguides, both with a 4 µm poling period but with two different top widths: 1440 and 1380 nm (a). The linear optical transmission at the first- and second-harmonic wavelengths was measured, allowing the fiber-to-chip coupling losses were calibrated and extracted from this data. An expanded view of the measured curve for the waveguide with a 1440 nm width is compared to a theoretical curve and a theoretical curve corrected for inhomogeneous broadening (b).
    Research

    Wavelength Conversion: PPLN waveguide wavelength-conversion efficiency improves by a factor of 20

    John Wallace
    Dec. 2, 2018
    Periodically poled lithium niobate waveguides are efficient wavelength converters—now, with subwavelength confinement and precise poling, they have become much more so.
    Akira Hiruma, president and CEO of Hamamatsu Photonics.
    Test & Measurement

    Business Forum: Photons are good business -- An interview with Akira Hiruma

    Conard Holton
    Dec. 2, 2018
    An interview with the CEO of Hamamatsu Photonics shows how an engineering company with a singular focus on photonics can succeed.
    FIGURE 1. Shape factors are shown for different lens configurations, assuming an infinite conjugate to the left of the lenses.
    Optics & Design

    Aspheres: The impact of shape factor on asphere design

    Eduardo Gonzalez
    Dec. 2, 2018
    An aspheric lens of a certain power can have many shapes; matching the shape factor of the lens to its application is important.
    FIGURE 1. An illustration shows single-bit QIS image capture and computation.
    Research

    Advances in Detectors: The Quanta image sensor (QIS): Making every photon count

    Dec. 2, 2018
    Demonstrating single-photon sensitivity at room temperature without avalanche multiplication, QIS technology offers sub-diffraction-limited pixel sizes and many degrees of freedom...
    (All figures courtesy of the University of Kassel)
    FIGURE 1. This schematic shows a simple spectroscopy setup at the University of Kassel for absorption measurements in which the probe gas is expanded through a slit nozzle into a vacuum chamber, creating a supersonic jet; light from an IR laser passes through the jet and the light intensity is recorded with an IR detector.
    Research

    Optical Parametric Oscillators: Ultrastable tunable laser sources serve IR spectroscopy for astrophysics

    Dec. 2, 2018
    An ultrastable continuous-wave optical parametric oscillator light source is helping lab researchers study the chemistry of outer-space molecules.

    More content from Volume 54, Issue 12

    (Image credit: Erwin J. Alles, University College London)
    Whereas photoacoustic imaging generates sound signals through absorption of light by the object being imaged, this setup uses a dedicated optical ultrasound generator to produce acoustic signals that reflect off the specimen.
    Research

    In Vivo Imaging: All-optical setup makes ultrasound flexible

    Barbara Gefvert
    Dec. 2, 2018
    Optical production and sensing of ultrasound lead to an ultrasound probe that could be miniaturized for endoscopic applications.
    FIGURE 1. Advanced driver-assistance systems (ADAS) and fully autonomous vehicle (AV) systems depend on a variety of optoelectronic sensors (a) positioned on the moving vehicle (b) to ensure occupant safety.
    Software

    Photonics Applied: Transportation: Datasets accelerate integration of thermal imaging systems into autonomous vehicles

    Arthur Stout
    Dec. 2, 2018
    Thermal sensor datasets empower the automotive community to create safer and more efficient ADAS and driverless-vehicle systems in conditions of darkness and through fog and sun...
    (Courtesy of Waymo)
    Waymo’s fully self-driving Chrysler Pacifica hybrid is seen on a public road in Chandler, CA.
    Test & Measurement

    Automotive Lidar: Lidar for self-driving cars comes in many competing forms

    Jeff Hecht
    Dec. 2, 2018
    For autonomous vehicles, a choice remains between spinning scanning, solid-state scanning, time of flight, flash, and coherent lidar.
    (Courtesy of Cornell University)
    Enabled by new light sources providing maximum flexibility for optimizing parameters, three-photon microscopy allows nondestructive imaging deep into a wide variety of specimens. This micrograph was acquired at 1330 nm (3 MHz) using a fiber laser designed to optimize three-photon fluorescence excitation in multiphoton imaging (KMLabs’ Y-Fi OPA); it shows mouse brain vasculature and neurons (labeled with fluorescein isothiocyanate-conjugated dextran and green fluorescent protein, respectively).
    Research

    Multiphoton Imaging/Light Sources: New flexibility for deep, nondestructive imaging

    Dec. 2, 2018
    Laser innovations that enable balancing of critical parameters provide unprecedented options for quick, nondestructive, high-quality imaging deep into tissue.
    Content Dam Lfw Print Articles 2018 12 1812lfw Nb F5
    Lasers & Sources

    Pressurized semiconductor membrane becomes widely tunable light emitter

    John Wallace
    Dec. 1, 2018
    An indium gallium nitride membrane, when pressurized like a balloon, shifts its near-IR output wavelength by more than 250 nm and could lead to similar widely tunable lasers.
    Content Dam Lfw Print Articles 2018 12 1812lfw Nb F4
    Research

    Near-infrared metasurface reflects only one direction of circularly polarized light

    John Wallace
    Dec. 1, 2018
    A chiral optical metasurface selectively absorbs either left- or right-handed circularly polarized light; it could be useful in imagers and other optical systems.
    (Courtesy of the Holst Centre)
    FIGURE 1. A microLED panel shows how the tiny, closely spaced pixels can be integrated into flexible materials for personal wearable displays.
    Software

    Technology Review: Laser Focus World’s top 20 photonics technology picks for 2018

    John Wallace
    Dec. 1, 2018
    2018 produces another crop of innovations in photonics that will affect industry, science, academia, and everyone else as well.
    (Image credit: Hamamatsu Photonics)
    A phase mask created using standard software forms part of the photonic crystal gain cavity of the integrable phase-modulating surface-emitting laser (iPMSEL; a); here, the complex phase mask spells out the text “iPM Lasers” in the far field of the 2D pattern-emitting semiconductor laser (b).
    Lasers & Sources

    Semiconductor Lasers: Phase-modulating semiconductor laser projects 2D beam patterns without HOEs or SLMs

    Gail Overton
    Dec. 1, 2018
    The gain medium of a semiconductor laser is modified with a photonic crystal lattice and an integrable, configurable phase mask that produces a 2D beam pattern of emission in ...
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    Optics & Design

    3D eye simulation directs noninvasive process to prolong glasses-free vision

    Gail Overton
    Dec. 1, 2018
    By modeling the complete optical parameters of the human eye using COMSOL Multiphysics software, a prescription for a series of noninvasive laser procedures for presbyopia patients...
    Research

    Ultrafast laser spectroscopy may open door to efficient clean industrial fuels

    John Wallace
    Dec. 1, 2018
    Combining CCD TDI pixels and CMOS readout technology, the UV line-scan imager uses backside illumination and a UV-specific antireflection coating to reach high quantum efficiency...
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    Detectors & Imaging

    UV-sensitive TDI imager combines the best of CCD and CMOS technology

    Gail Overton
    Dec. 1, 2018
    Combining CCD TDI pixels and CMOS readout technology, the UV line-scan imager uses backside illumination and a UV-specific antireflection coating to reach high quantum efficiency...
    2105 Lfw Lpms Supp 9a
    Research

    Trade, tariffs, and tumult

    John Lewis
    Dec. 1, 2018
    Editor in Chief John Lewis invites you to Laser Focus World’s 31st Annual Lasers & Photonics Marketplace Seminar.
    (Image credit: M. I. Bodnarchuk/Empa)
    Assemblies of colloidal nanocrystals—called superlattices—are shown under white-light illumination; the superlattice structures are composed of 3D cubic-shaped collections of quantum dots with similar physical sizes and optoelectronic emission properties.
    Research

    Quantum-dot-based Light Sources: Perovskite quantum-dot superlattices produce superfluorescent quantum light

    Gail Overton
    Dec. 1, 2018
    Superlattices of highly monodispersed lead-halide perovskite quantum dots, when illuminated, spontaneously synchronize their quantum-mechanical phase, producing superfluorescence...