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    • Volume 53, Issue 08

    More content from Volume 53, Issue 08

    A spherical mirror isolates a cryogenically cooled infrared focal-plane array (IRFPA) from the internal stray light produced by the surrounding optical/mechanical system. In this schematic, the intersection of the optical axis with the IRFPA is termed O and radius and height of the spherical mirror are R and H, respectively. B and C are points at the opposite edges of the entrance pupil; the critical rays that determine the spherical mirror's range are rays AB and AC. Because the self-radiation of the spherical mirror itself is extremely low, it can be ignored.
    An approach to experimentally measure internal stray radiation of cryogenic IR imaging systems uses only a spherical mirror.
    Aug. 11, 2017
    (Courtesy of Technion – Israel Institute of Technology)
    From a standard exposure of a lit room, computational imaging can be used along with a bulb-response function (BRF) database to show how the scene appears with only one bulb type or how it can be enhanced by computationally selecting different artificial illumination sources.
    The alternating-current-enabled camera can be used internationally under 110V or 220V standard lighting conditions.
    Aug. 11, 2017
    (Courtesy of the University of Texas, Austin/Milner group)
    As a typical acoustic neuroma enlarges, it puts pressure on both the facial and cochlear nerves, making it a challenge to surgically remove the neuroma using traditional cutting tools without damaging these nerves (a; courtesy of The Mayo Institute). In another potential surgical application for a thulium laser, a blood vessel embedded in a tissue phantom (b) is shown after laser passes were made over the tissue (c), whereby the vessel was spared.
    Thulium-doped fiber lasers are of increasing interest for life science applications for two key reasons.
    Aug. 11, 2017
    (Courtesy of Art Photonics)
    Porcine tissue samples from fatty muscle (left) and heart muscle (right) cut with light from CO (top) and CO2 (bottom) lasers operating at an 8 W output at a speed of 4 mm/s are compared, with the beam focused 2 mm below tissue surface in all cases; the white zone shows the extent of coagulation. These cross-sectional microscope images were taken after perpendicular cuts with a scalpel.
    Carbon monoxide (CO) and carbon dioxide (CO2) lasers are somewhat similar mid-infrared sources with very different histories.
    Aug. 11, 2017
    Analysis of high-resolution intravital z-section imagery enables generation of 3D flow maps depicting the microvascular network in a healthy mouse brain; velocity is noted in μm/s.
    The particles provide a dramatically higher emission quantum yield, and can be easily modified for various functional-imaging applications.
    Aug. 11, 2017
    (Courtesy of Nanjing University)
    Spectra are shown for a tunable carbon-nanotube mode-locked thulium fiber laser (a) and a tunable graphene-saturable-absorber mode-locked Cr:ZnS laser (b).
    Researchers are using carbon-based nanomaterials to enable record tuning range from compact and low-cost 2-micron laser oscillators.
    Aug. 11, 2017
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    This month, I interviewed Dr. Jason Eichenholz, CTO and co-founder of Luminar Technologies.
    Aug. 11, 2017
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    Supercontinuum generation from 1 to 11.5 μm from a tapered chalcogenide photonic-crystal fiber has been demonstrated.
    Aug. 9, 2017
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    Researchers have completely bypassed the problems created by the use of dispersive optics to create femtosecond optical vortices.
    Aug. 9, 2017
    An optically transparent half-wavelength microwave antenna made by layering monolayer graphene onto glass has been created.
    Aug. 9, 2017
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    A different type of fiber Bragg grating (FBG)-based sensor has 1000X more sensitivity than standard FBG sensors.
    Aug. 9, 2017
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    Two independent lasers, each with their own silicon Fabry-Perot cavities and with laser linewidths of just 0.01 Hz, have been created.
    Aug. 9, 2017
    Conard Holton2
    Photonics applications in the life sciences have long been some of the most compelling and exciting uses of the technology.
    Aug. 9, 2017