Table of ContentsFeaturesTHIN-FILM METROLOGY: Ellipsometry provides detailed analysis of infrared optical thin filmsModern IR-spectroscopic ellipsometry instruments and data analysis software provide accurate and repeatable thickness and optical property measurements of substrates and film samples. AVALANCHE PHOTODIODES: Si charge avalanche enhances APD sensitivity beyond 100 GHzMade with readily available group IV germanium and silicon materials, a CMOS-compatible waveguide-integrated avalanche photodiode offers a gain-bandwidth of 105 GHz, extending Ge/Si APDs to high-bandwidth chip-to-chip interconnects and high-sensitivity fiber-optic communications. ASPHERES: Variable optical null advances asphere metrologyRemoving astigmatism and coma with a variable optical null allows an aspheric stitching interferometer to measure surfaces with departures up to 1000 waves from the best-fit sphere. PHOTONIC FRONTIERS: NEXT-GENERATION PHOTOVOLTAICS: New techniques boost photovoltaic efficiencySolar cell performance has been improving slowly for years. Now developers are exploring new designs and structures, which they hope can give a big boost to energy conversion efficiency. MULTISPECTRAL IMAGING: Imaging systems can benefit from reflective opticsReflective optical systems can handle high power across a broad wavelength spectrum and may provide a less complex and lower-cost alternative to refractive systems. NewsbreaksOptofluidic system for laser tweezers has no pesky cover slipA new version of a type of optofluidic system designed to be used with laser "tweezers" for 3D manipulation of biological cells under a microscope has been created by researchers at Technische Universitvät Ilmenau (Ilmenau, Germany). Hollow fiber transmits peak power of 11.4 MWWith their lack of self-phase modulation and core optical absorption, hollow optical fibers are an excellent way to transmit high-peak-power optical pulses. VECSEL produces 2.1 W of single-frequency, low-noise lightAn optically pumped room-temperature vertical-external-cavity surface-emitting laser (VECSEL) developed by researchers at the Institut d'Electronique du Sud, Université Montpellier (Montpellier, France) and the Laboratoire de Photonique et Nanostructures (Marcoussis, France) reaches an output of 2.1 W of low-noise (37 kHz linewidth), single-frequency TEM00 operation with a beam quality (M2) of 1.2 at a wavelength of 1015 nm. Adjustable linewidth laser simplifies, reduces testing costsIn optical communications and other semiconductor-laser-based systems, testing the impact of laser linewidth at the source used to require purchase of several different lasers with varying linewidth parameters. A single view yields 3D x-ray diffractive imagesResearchers at the University of California–Los Angeles (Los Angeles, CA), the University of Colorado at Boulder (Boulder, CO), and the University of North Texas (Denton, TX) have for the first time demonstrated ankylography–3D coherent x-ray diffractive imaging that could find applications in imaging thick or embedded structures where slicing for electron or confocal microscopy is not feasible. Metamaterial enables darker-than-black radiation absorptionNon-diffraction-limited hyperbolic metamaterials are not only finding applications as hyperlenses and photonic funnels but can also be used as highly efficient radiation absorbers, with nearly all incident light "sucked" into the metamaterial medium. World NewsULTRAFAST SOURCES: 2.8 fs deep-UV pulses are spectroscopist's toolFemtosecond and attosecond light pulses are now allowing scientists to deeply explore the workings of atoms, molecules, and nanoparticles. MICROSCOPY: 4D imaging realized with PINEMTransmission electron microscopy (TEM) continues to be a powerful imaging tool at the nanometer scale and below. PHOTOLITHOGRAPHY: Holography makes a bid in the search for maskless lithographyThe hunt for the next big thing–or small thing–in lithography could do away with photomasks in favor of holograms, according to researchers at the University of Cambridge (England). TERAHERTZ DETECTION: Terahertz remote sensing uses 'all-optical' fluorescence manipulation techniqueAlthough many time-domain terahertz-wave detection techniques have been developed, high ambient-moisture absorption rules out "remote" terahertz sensing, shutting out a host of applications in homeland security, astronomy, and environmental monitoring. DEPTH-OF-FOCUS ENHANCEMENT: Simple wavefront-coding setup is adjustable in real timeAn optical technique called "wavefront coding," invented by Ed Dowski and Thomas Cathey at the University of Colorado (Boulder, CO) in the mid-1990s, provides a simple, effective way to increase depth of focus in many imaging systems. LIGHTING: Tailored emissivity paves way for 400 lm/W incandescent lampsJust when you thought incandescent light bulbs were dead, researchers at Stanley Electric Corp. (Tsukuba, Japan), Osaka University (Osaka, Japan), Shizuoka University (Shizuoka, Japan), and the National Institute of Advanced Industrial Science and Technology (Tsukuba, Japan) have modified the blackbody radiation of an incandescent bulb, demonstrating the possibility of 95% electric power to visible-light conversion and paving the way for luminous efficiencies beyond 400 lm/W. ColumnsThe Editors' DeskMeasures of ProgressBy any measure, last month's SEMICON West event in San Francisco, CA provided a welcome boost to photonics market watchers.
In My ViewIN MY VIEW: Lighter fare for your vacation readingIn the course of my research of suitable science books for your summer reading, I came across a list of books that have been entered for the British Royal Society's annual prize for science books.
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