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  • Volume 51, Issue 04

    • Volume 51, Issue 04

    1504lfw 26
    Optics

    Does photonics matter to your state?

    April 8, 2015
    Knowledge is power. What could you do if you knew all of the photonics companies in your state?
    FIGURE 1. Schematics of the difference frequency generation nonlinear process (a) and the picosecond mid-IR tunable source (b). Wavelength, synchronization, and dither control are all electronically controlled. By combining light from these two fiber-based lasers in a nonlinear crystal, it is possible to shift the laser wavelength to different spectral regions such as visible, near-IR, or mid-IR (3 to 4 μm and 6 to 12 μm).
    Test & Measurement

    Fiber Lasers: Mid-IR laser source is widely tunable for standoff explosives detection

    April 8, 2015
    Nonlinear frequency mixing of a picosecond fiber-based programmable laser and a tunable MOPA results in a widely tunable laser source in the fingerprint region for remote molecular...
    Satellite-to-satellite secure interferometric communications could enable simpler, smaller, and less expensive communications systems.
    Optics

    Interferometry: Quantum entanglement physics secures space-to-space interferometric communications

    F. J. Duarte
    April 8, 2015
    Interferometric optical communications can potentially lead to robust, secure, and naturally encrypted long-distance laser communications in space by taking advantage of the underlying...
    Courtesy of TRUMPF
    FIGURE 1. Micro bicycle cut with an ultrashort pulse laser, standing next to a 2 Euro coin for size comparison.
    Lasers & Sources

    Ultrafast Lasers: Ultrashort pulse lasers bring cost-efficient precision to micromanufacturing

    April 8, 2015
    Ultrafast thin disk and fiber lasers deliver the cold ablation material processing required for high-value, high-volume products such as smartphones, automobiles, and medical ...
    FIGURE 1. Fiber drawing that includes a conventional UV-cured acrylate coating process.
    Fiber Optics

    Fiber-Optic Components: Harsh-environment optical fiber coatings: Beauty is only skin deep

    April 8, 2015
    Successful deployment of optical fibers in harsh environments for oil and gas, nuclear, medical, and aerospace applications depends far more on the fibers' immediate external ...

    More content from Volume 51, Issue 04

    (Courtesy of GE R&D Center Press office)
    FIGURE 1. Robert N. Hall (center) with Gunther Fenner (left) and Jack Kingsley (right) at the General Electric Research & Development Center, where they made the first laser diode in 1962.
    Lasers & Sources

    Photonic Frontiers: Laser diodes: Looking back/Looking forward: Laser diodes have come a long way and brought five Nobel prizes

    Jeff Hecht
    April 8, 2015
    Once the weaklings of the laser world, unable to emit a few milliwatts continuously at room temperature, laser diodes have become workhorses. Today, they power the Internet, pump...
    Conard Holton2
    Optics

    Photonics awareness

    Conard Holton
    April 8, 2015
    In considering what to write for this Editor's Desk, I made a list of article topics published in the issue that could reveal a theme.
    VU University
    In synthetic-aperture OCT, the insets (i)–(iii) describe the three light propagation paths that constitute three separate optical apertures; L = lens, PP = annular phase plate, CL = collimator, M = mirror, FC = fiber coupler, CIR = circulator, PR = photon receiver, FBG = fiber Bragg grating, and BD = balanced detector. Digital manipulation of the data sets produces extended depth-of-field OCT imaging as evidenced by consistent focus of uniform spheres in an elastomer matrix (b) compared to out-of-focus spheres using standard OCT imaging methods (a).
    Test & Measurement

    Optical Coherence Tomography: Synthetic aperture OCT extends focal depth in biological tissues

    Gail Overton
    April 3, 2015
    In optical coherence tomography (OCT) imaging, a high lateral resolution typically means a short depth of field or reduced axial resolution.
    Courtesy Towson University
    Microscope images show the diluted cobalt-nanoparticle-based ferrofluid before (a) and after (b) applying an external magnetic field; the fluid separates into cobalt-rich and cobalt-poor phases creating self-assembled stripes oriented along the direction of the magnetic field.
    Optics

    Metamaterials: Tunable hypercrystals merge best of photonic crystals and metamaterials

    Gail Overton
    April 3, 2015
    Researchers have combined the most interesting properties of photonic crystals and hyperbolic metamaterials into an entirely new material.
    Graphics by Yulia Teryaeva
    Based on multilayer poling technology they have already proven on flat surfaces, researchers at Carleton University and the COPD at Université Laval will be developing a radially poled nonlinear optical fiber to be paired with a fiber laser for second-harmonic generation (SHG). Here, an artist’s concept shows a conventional fiber spliced to the SHG optical fiber, showing its multilayered poled core and internal poling electrodes.
    Optics

    Nonlinear Optical Fiber: All-fiber frequency doubler with engineered glass microlayers under development

    John Wallace
    April 2, 2015
    A professor has received a grant to develop a new optical-fiber-based method of frequency conversion of light and other nonlinear-optical operations on light.
    Courtesy University of Illinois at Urbana-Champaign
    A schematic diagram shows slow light, fast light, and one-way light blocking using BSIT in a series of silica microresonators (slow/red, fast/blue; central yellow shows blocking effect).
    Optics

    Optical Physics: Brillouin-scattering-induced transparency leads to nonreciprocal optical waveguides

    John Wallace
    April 2, 2015
    A team of researchers is using Brillouin-scattering-induced transparency (BSIT) to create one-way optical waveguides.
    Courtesy Monash University
    A model depicts light scattering and calculated scattering cross-section spectra of an incident plane wave by a cubic nanoparticle (a). The numerically calculated scattering cross-section spectra for a Si nanocube (SiNC) of width W = 200 nm, an equivolume Si nanosphere (SiNS) of diameter D = 248.14 nm, and an equidimensional SiNS with D = 200 nm are shown (b). The scattering cross-section versus wavelength for a W = 200 nm nanocube with different permittivities is displayed (c).
    Lasers & Sources

    Nanophotonics: Cubic nanoantennas (nanocubes) efficiently direct light

    Gail Overton
    April 1, 2015
    Cube-shaped, tiny, resonant optical antennas improve over spherical nanoantennas for directing ultranarrow beams of light where needed.
    A computer-generated hologram (CGH) serves as a null corrector in a Fizeau interferometer used for testing an aspheric surface. The CGH can be placed on either side of the focus. An improved method of aligning a CGH relative to the focus has been developed and has undergone first tests.
    Optics

    Optical Testing: Quantitative approach improves CGH alignment for asphere testing

    John Wallace
    April 1, 2015
    Testing the form of a rotationally symmetric aspheric surface to be made in quantity is often done using a computer-generated hologram (CGH).
    Content Dam Lfw Print Articles 2015 04 1504lfw Nb Microstructures Web
    Detectors & Imaging

    Optical microstructures act as secure product identifiers

    March 31, 2015
    A set of algorithms can robustly ascertain an object’s authenticity using optically acquired microstructures.
    Content Dam Lfw Print Articles 2015 04 Lfw April Bf Ursi Kurt Web
    Optics

    Business Forum: Best practices from Switzerland— Photonics and otherwise

    Milton Chang
    March 30, 2015
    This month I interview the husband–wife team of Professor Ursula Keller and Dr. Kurt Weingarten.
    Content Dam Lfw Print Articles 2015 04 1504lfwnb Pipeline Web
    Test & Measurement

    Standoff Raman spectrometer identifies liquids in gas pipelines

    March 30, 2015
    A standoff Raman spectrometer allows sensing from 2.4 m away at standard 2-m-height standoff pipes in the network.
    Content Dam Lfw Print Articles 2015 04 Nb Autism
    Software

    Facial recognition algorithm identifies severity of autism

    March 30, 2015
    Scientists have established that algorithms applied to facial surface measurements can identify the severity of autism spectrum disorders.