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    • Volume 51, Issue 04

    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.
    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...
    April 8, 2015
    Conard Holton2
    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.
    April 8, 2015
    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).
    In optical coherence tomography (OCT) imaging, a high lateral resolution typically means a short depth of field or reduced axial resolution.
    April 3, 2015
    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.
    Researchers have combined the most interesting properties of photonic crystals and hyperbolic metamaterials into an entirely new material.
    April 3, 2015
    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.
    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.
    April 2, 2015
    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).
    A team of researchers is using Brillouin-scattering-induced transparency (BSIT) to create one-way optical waveguides.
    April 2, 2015
    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).
    Cube-shaped, tiny, resonant optical antennas improve over spherical nanoantennas for directing ultranarrow beams of light where needed.
    April 1, 2015
    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.
    Testing the form of a rotationally symmetric aspheric surface to be made in quantity is often done using a computer-generated hologram (CGH).
    April 1, 2015
    Content Dam Lfw Print Articles 2015 04 1504lfw Nb Microstructures Web
    A set of algorithms can robustly ascertain an object’s authenticity using optically acquired microstructures.
    March 31, 2015
    A picosecond-laser-based microwelding process can join glass to silicon (Si) quickly and with high mechanical strength.
    March 31, 2015
    Content Dam Lfw Print Articles 2015 04 Lfw April Bf Ursi Kurt Web
    This month I interview the husband–wife team of Professor Ursula Keller and Dr. Kurt Weingarten.
    March 30, 2015
    Content Dam Lfw Print Articles 2015 04 1504lfwnb Pipeline Web
    A standoff Raman spectrometer allows sensing from 2.4 m away at standard 2-m-height standoff pipes in the network.
    March 30, 2015
    Content Dam Lfw Print Articles 2015 04 Nb Autism
    Scientists have established that algorithms applied to facial surface measurements can identify the severity of autism spectrum disorders.
    March 30, 2015