• Back Issues >
  • Laser Focus World >
  • Volume 49, Issue 08

    • Volume 49, Issue 08

    FRONTIS. In aerospace component drilling tests, a single 10 ms pulse from a square output fiber laser can produce a large square entrance hole at focus.
    Aug. 13, 2013
    Fiber lasers offer an alternative to pulsed Nd:YAG lasers for drilling cooling holes in turbine components, enabling manufacturing processes to increase production rates, provide...
    FIGURE 1. OCT imaging can provide real-time in vivo cross-sectional visualization of the internal tissue microstructure morphology by interferometrically measuring the phase delay of the injected light beam (a) using a fiber probe (b).
    Jean-Michel Pelaprat
    Aug. 13, 2013
    Fiberoptic processing technologies such as filament fusion can be used to fabricate probes for biomedical imaging techniques ranging from coherent detection via OCT to spectroscopy...
    (Courtesy of Philips Color Kinetics)
    White LEDs tunable to emit different shades of white on the San Francisco Oakland Bay Bridge.
    Jeff Hecht
    Aug. 13, 2013
    Blending red, green, and blue LED emissions brings new capabilities to solid-state lighting -- tunable colors can be decorative, eye-pleasing, relaxing, and even help you get ...
    (Courtesy of Ophir Photonics Group)
    FIGURE 1. A USB camera with a 4X expanding lens (a) is used along with a fixturing assembly (b) to measure the size and shape of holes in a molded device. The fixturing assembly has a vertical light source that illuminates the device being inspected; the USB camera and expansion lens are beneath the device. The holes have a diameter and depth
    Aug. 13, 2013
    Laser-beam diagnostic software has some surprising use—for example, as a machine-vision tool for inspecting the size and shape of holes during manufacture.
    Victor Liu
    Milton Chang
    Aug. 13, 2013
    In this column, I interview Victor Liu, president of Focuslight, a maker of high-power laser diodes, about being an entrepreneur in China.

    More content from Volume 49, Issue 08

    Various types of IR illumination sources are compared (a); typical emission spectra (b) for IR LEDs (dashed line) and IR VCSELs (solid line) are shown at reference temperature (blue) and reference temperature +70°C (red).
    Gail Overton
    Aug. 13, 2013
    Oclaro’s high-power 850 nm vertical-cavity surface-emitting laser (VCSEL) arrays suit numerous IR illumination applications -- including gesture-recognition technology and proximity...
    Conard Holton2
    Conard Holton
    Aug. 12, 2013
    The creation of the Center for Freeform Optics is major news indeed.
    A 12-core optical fiber with a 230 µm cladding diameter and individual core effective areas of 105.8 µm2 can transmit 409 Tbit/s in each direction, for a total of 818 Tbit/s. The core positions are interleaved so that they alternate in propagation direction (shown as red and blue).
    John Wallace
    Aug. 12, 2013
    A team of primarily Japanese engineers has demonstrated transmission of data over a 450 km section of multicore optical fiber at rates that approach a petabit per second.
    Thermal noise for a conventional dielectric multilayer coating (with 20 periods of alternating SiO2/Ta2O5 with a half-wavelength SiO2 cap) is compared to that of a GaAs/AlGaAs crystalline coating, clearly showing the tenfold reduction in Brownian motion (green line). The orange line shows thermal noise of the dielectric multilayer, and the blue line shows the thermal noise of the crystalline coating, which includes both the Brownian (green) and thermo-optic noise (cyan).
    Gail Overton
    Aug. 12, 2013
    Ultrasensitive interferometers and ultrastable laser sources depend on cavity mirrors that exhibit excellent optical and mechanical performance.
    Courtesy of NIF
    A high-energy petawatt laser, the Advanced Radiographic Capability (ARC), will conduct multiframe, hard-X-ray radiography of imploding NIF capsules. The short pulses for ARC will be produced by compressing the laser pulse, with gratings in the large ARC compression chamber shown in the photo.
    Jeff Hecht
    Aug. 9, 2013
    Markups of the fiscal 2014 energy budget by the U.S. House and Senate Appropriations Committees provided only a small amount of good news for laser-fusion labs.
    Courtesy of Sentinel Photonics
    An ultracompact multipass gas cell being commercialized by Sentinel Photonics uses a new optimization method to increase the optical path length of the device in a very small package, with dense spot patterns far more complex than typical circular or elliptical beam patterns.
    Gail Overton
    Aug. 8, 2013
    With an aim to create gas cells that deliver long absorption path lengths in a smaller package, president and cofounder of Sentinel Photonics Stephen So spent several months writing...
    Content Dam Lfw Print Articles 2013 08 Nb Ge Si
    John Wallace
    Aug. 7, 2013
    Irish researchers have developed an asymmetrically doped wafer-bonded germanium silicon heterojunction photodiode that has a very high responsivity greater than 1 A/W for a 1....
    Content Dam Lfw Print Articles 2013 08 1308lfwbreaksf3web
    Gail Overton
    Aug. 6, 2013
    An international team of researchers has demonstrated that slightly twisted pairs of gold nanorods have a circular polarizing effect on light that is ten times stronger than the...
    Content Dam Lfw Print Articles 2013 08 1308lfwbreaksf2web
    John Wallace
    Aug. 6, 2013
    Luminescent solar concentrators consist of a flat pane of transparent material doped with dye fluorophores; some of the sunlight absorbed by the dye is re-emitted and totally ...
    Content Dam Lfw Print Articles 2013 08 1308lfwbreaksf1web
    Gail Overton
    Aug. 6, 2013
    Researchers at Ecole Polytechnique Federale de Lausanne (EPFL) have been able to fabricate MoS2-based photodetector devices that are five times more light-sensitive than silicon...