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  • Volume 53, Issue 12

    • Volume 53, Issue 12

    FIGURE 1. This diagram shows a strongly injection-locked whistle-geometry semiconductor ring laser (WRL) monolithically integrated with a single-frequency master laser. The arrows indicate directions of the light injected from the master laser into the ring laser, unidirectional light propagation in the ring laser, and the light outcoupled from the ring laser to the optical output waveguide.
    Lasers & Sources

    Ultrafast Lasers: Injection-locked microring diode lasers enable ultrafast data transport

    Dec. 1, 2017
    Ultrafast monolithically integrated optoelectronic circuits with strongly injection-locked microring lasers could increase optical-fiber-based transmission capacity tenfold.
    Courtesy of Olympus
    These images were acquired using various Olympus IR objective lenses, a BX2M-IR upright compound microscope, an XM10-IR digital camera, and Olympus Stream software: 10x (a), 20x (b), 50x (c), and 100x (d).
    Optics

    Scientific Imaging: Near-IR microscopes image through silicon without damaging the finished product

    Robert Bellinger
    Dec. 1, 2017
    Imaging through silicon with dedicated IR objective lenses enables nondestructive flip-chip analysis and other essential evaluations.
    (Used with permission from Science Translational Medicine)
    FIGURE 1. Arany and his colleagues researching light-facilitated dentin generation used poly-lactide-co-glycolide (PLG) scaffolding to assess three-dimensional differentiation of the subject's own stem cells.
    Research

    Photobiomodulation: Regeneration without risk: Light-enabled tissue repair

    Barbara Gefvert
    Dec. 1, 2017
    The noninvasive application of light to regrow teeth -- and potentially to recover the functionality of damaged organs -- is an appealing alternative to current options. Misunderstandin...
    Courtesy of Y. Guo
    FIGURE 1. A part made using less optimized material; shown is powder bed fusion using amorphous thermoplastic polylactic acid (PLA) [5].
    Lasers & Sources

    Photonics Applied: 3D Laser Printing: Selecting and using materials for additive manufacturing processes

    Dec. 1, 2017
    Certain polymers, metals, and ceramics are better suited for AM than others, and there are differences among the multiple AM approaches.
    (Courtesy of Draper)
    FIGURE 1. A prototype cyborg dragonfly carries sensors and a photovoltaic power supply; the addition of optogenetically controlled steering will complete the conversion of this insect into a tiny externally controlled drone that can continually power itself by pausing to eat other insects.
    Lasers & Sources

    Technology Review: Laser Focus World's top 20 photonics technology picks for 2017

    John Wallace
    Dec. 1, 2017
    Optics and photonics contribute hugely to the digital revolution and are in turn furthered by it. Some of these contributions are evident to the average tech-savvy but nonspecialist...

    More content from Volume 53, Issue 12

    (Courtesy of Seongwoo Yoo)
    Simulations of a Gaussian beam propagating through a conventional graded-index-core fiber without (a) and with (b) laser gain show the appearance of higher-order modes (HOMs). However, if a graded-index core is placed in a gain-guided and index-antiguided (GG + IAG) fiber design (not shown), fundamental-mode propagation is maintained even under amplification.
    Fiber Optics

    Large-mode-area graded-index fiber design to boost fiber-laser powers

    John Wallace
    Dec. 1, 2017
    Two researchers have taken a different approach to large-mode-area fiber design by changing the gain-guided and index-antiguided fiber design, which is conventionally step-index...
    Mean emission wavelengths for assigned molecules in AD and N brain tissues differ by excitation wavelength.
    Research

    Spectroscopy indicates biomarkers for Alzheimer's disease

    Barbara Gefvert
    Dec. 1, 2017
    Label-free optical spectroscopy may enable operational insight into Alzheimer's disease and perhaps even early diagnosis so that patients can make decisions while still cognitively...
    (Courtesy of Bilkent University and Middle East Technical University)
    A pulsed 1550 nm laser beam creates (a) 1 μm spherical structures (voxels) in silicon, as well as (b) rods created by nonlinear interactions of the beam as a function of the number of pulses applied. By scanning the laser beam to create voxel and rod patterns, in-chip structures such as a 600 × 600 pixel hologram of the Mona Lisa (c), as well as selectively etched structures (d and e) can be fabricated, further extending the possibilities for 3D silicon photonics.
    Optics

    'In-chip' devices enable truly 3D silicon photonics

    Gail Overton
    Dec. 1, 2017
    A team of researchers has fabricated "in-chip" microstructures and photonic devices deep within silicon using nonlinear laser lithography that enable dense, truly 3D silicon photonics...
    (Photo by Nick Gonzales)
    Plants grown in this luminescent solar concentrator (LSC)-equipped greenhouse fared as well or better than plants grown in conventional greenhouses; these LSCs convert about 4% of the sunlight striking them to electricity.
    Optics

    Luminescent solar concentrators atop greenhouses harvest power, don't hurt plant growth

    John Wallace
    Dec. 1, 2017
    Brightly colored research greenhouses equipped with electricity-producing luminescent solar concentrators take light only from the spectral regions that are less needed by the...
    1712lfw Nb F4
    Research

    Beyond hydrogel: Stretchy PDMS optical fibers make better biosensors

    Gail Overton
    Dec. 1, 2017
    A biosensor that uses polydimethylsiloxane (PDMS) dye-doped optical fibers is more thermally and environmentally stable than when using hydrogel fibers.
    Content Dam Lfw Print Articles 2017 12 1712lfw Nb F3
    Research

    Backscattering of terahertz pulses produces single-cycle attosecond pulses

    John Wallace
    Dec. 1, 2017
    The design contains a laser-plasma wakefield accelerator to produce a high-quality relativistic electron beam, and a terahertz light source capable of producing a single-cycle...
    Content Dam Lfw Print Articles 2017 12 1712lfw Nb F2
    Lasers & Sources

    3D-SHOT performs optogenetic brain stimulation with single-neuron resolution

    Gail Overton
    Dec. 1, 2017
    A new multiphoton excitation technique allows on-demand optogenetic photostimulation of custom neuron ensembles.
    Content Dam Lfw Print Articles 2017 12 1712lfw Nb F1
    Detectors & Imaging

    Beam power meter for x-ray free-electron lasers is compact, durable

    John Wallace
    Dec. 1, 2017
    Researchers at the Free-Electron Laser in Hamburg have come up with a bolometric radiometer that is only 26 mm on a side, enabling easy measurement of a free-electron laser beam...
    Conard Holton2
    Lasers & Sources

    Beyond listicles, the best of photonics

    Conard Holton
    Dec. 1, 2017
    Although digital marketers can be accused of transforming "listicles" -- web articles in the form of lists -- into a simplistic tool for generating clicks, Laser Focus World has...
    Courtesy of WISTA-Management GmbH
    After investing about 1 billion euros of taxpayer money, Berlin-Adlershof has turned to Germany’s biggest technology park, creating several billion euros in revenue each year.
    Lasers & Sources

    Business Forum: What it takes to build a photonics hotspot

    Andreas Thoss
    Dec. 1, 2017
    The week of October 16, 2017 was Photonics Week in Berlin, and the local photonics community convened in Adlershof. The meeting attracted around 500 people. Not much for a big...
    FIGURE 1. Shown is the typical control loop used within an Observer-based digital servo.
    Positioning, Support & Accessories

    Beam Steering: Laser materials processing drives new servo control technologies

    Dec. 1, 2017
    As laser materials processing applications become more challenging, digital servos must steer laser beams with higher precision, flexibility, and finesse than their analog predecessors...