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  • Volume 54, Issue 05

    • Volume 54, Issue 05

    A 3D surface projection of live U-2 OS cell from a SLIM quantitative phase image is shown.
    Research

    Quantitative Microscopy/Drug Discovery: Adding on deep-tissue, subcellular, quantitative phase imaging

    Dr. Gabriel Popescu, Ph.D.
    May 2, 2018
    Label-free, quantitative 3D tomography can now image thick, strongly scattering tissues with nanometer resolution and remarkable contrast.
    Practical applications of holography range from security holograms on credit cards, bank notes, and passports, to medical imaging and augmented reality.
    Lasers & Sources

    Diode Lasers: Direct and frequency-converted diode lasers provide all wavelengths for holography

    May 2, 2018
    Laser diodes now fulfill the technical requirements to perform holography and lithography applications at new wavelengths in the UV and visible ranges.
    FIGURE 1. A comparison (a) of the signal-to-noise ratio vs. photon intensity for two types of Zyla cameras made by Andor Technology to that of the company’s iXon back-illuminated electron-multiplying CCD (EMCCD) shows that the EMCCD is best for the lowest photon rates, including single photon counting, while sCMOS takes over for higher (but still very low) photon rates). The quantum efficiency (QE) of Andor’s Zyla cameras is optimized for use with a range of fluorophores (b).
    Detectors & Imaging

    Photonics Products: Scientific CMOS Cameras: sCMOS cameras reach new levels of capability

    John Wallace
    May 2, 2018
    sCMOS cameras are now widely used in a variety of leading-edge microscopy techniques, as well as in astronomy and elsewhere.
    (Adapted from L. Jiang et al. [1])
    Improved models of electron dynamics helped researchers determine the best way to shape femtosecond pulses to improve micromachining; shown are calculated electron and phonon temperatures of 200 nm gold film irradiated by a 140 fs, 1053 nm laser pulse at a 0.2 J/cm2 intensity via the classical model (a) and the improved model (b).
    Lasers & Sources

    Laser Micromachining: Shaped femtosecond laser pulses improve ultrafast-micromachining quality

    John Wallace
    May 2, 2018
    The technique improves fabrication precision, quality, throughput, and repeatability, and effectively controls micro/nanoscale structures.
    A team from the German Research Centre for Environmental Health and the Technical University of Munich built this custom optoacoustic spectrometry (OAS) instrument. It includes a personal computer controlling a tunable nanosecond single optical parametric oscillator (OPO) light source with wavelength-dependent output power ranging from 0.5 to 20 mJ and wavelength scanning step set to 25 nm. A 95/5 beamsplitter reflects 5% of light exiting the laser to a photodiode, which triggers detection and power-per-pulse registration. The beamsplitter focuses most of the beam on the test chamber containing the sample—in this case, 400 ml distilled water solution with incrementing glucose concentrations. The beam, positioned perpendicular to the solution’s free surface, has a focal point at about 3 mm deep. Separated from the test chamber, the ultrasound detector was adjusted to accommodate the beam in its focus. Acquired signals first were amplified with a low-noise amplifier, then digitized by a data acquisition card operating at 100 megasamples/s. Solutions were maintained at a constant at 21°C in the test chamber.
    Research

    Photoacoustics/Spectrometry: Could optoacoustic spectrometry make noninvasive glucose monitoring viable?

    Barbara Gefvert
    May 2, 2018
    Among approaches proposed for noninvasive in vivo glucose monitoring, those based on spectroscopy show particular promise.

    More content from Volume 54, Issue 05

    (Courtesy of the Zheng Research Group, UT-Austin)
    The operation of optothermoelectric nanotweezers (OTENT) consists of surface modification of a metal nanoparticle by CTAC adsorption (a) and formation of CTAC micelles (b) and the counter-ions (c) that are randomly distributed without laser heating (d). Upon thermophoretic migration under laser heating (e), a thermoelectric field traps the metal nanoparticle (f) and creates both in-plane (g) and out-of-plane trapping force (h).
    Lasers & Sources

    Scientific Lasers: Optothermoelectric nanotweezers improve particle-trapping efficiency

    Gail Overton
    May 1, 2018
    Optothermoelectric nanotweezers, powered by simple optics, promise multiple innovations in nanophotonics and colloidal particle science.
    A machine-vision system for accurately finding defects on large industrial steel rollers includes a source of blue light, a line-scan camera, and a computer. The position of the roller as it is turned is measured by an encoder to coordinate roller orientation with the camera scans. The reason why it all works so well resides in the improved defect-finding algorithm.
    Test & Measurement

    Machine Vision: Improved optical-inspection algorithm finds defects on industrial steel rollers

    John Wallace
    May 1, 2018
    A newly developed machine-vision system can accurately measure roller surface defects.
    (Courtesy of MPQ)
    The dual-comb Doppler-free spectroscopy setup with two-photon excitation is shown.
    Spectroscopy

    Advances in Spectroscopy: Doppler-free two-photon, dual-frequency-comb spectroscopy demonstrated

    Gail Overton
    May 1, 2018
    Doppler-free recording of a species in a broadband frequency range spanning 10 THz has been demonstrated.
    Content Dam Lfw Print Articles 2018 05 1805lfw Nb F4
    Test & Measurement

    FMCW instrument with 10 µm ranging accuracy at 2 m uses low-cost VCSEL scanning

    John Wallace
    May 1, 2018
    A high-accuracy range-sensing system for noncontact shape measurement incorporates low-cost, rapidly modulated VCSELs.
    Content Dam Lfw Print Articles 2018 05 1805lfw Nb F5
    Lasers & Sources

    Sunlight and nanostructured hydrogel purifies and desalinates water

    Gail Overton
    May 1, 2018
    Researchers have developed a solar vapor generator from a novel hydrogel material that uses natural sunlight to efficiently produce purified and desalinated water.
    Content Dam Lfw Print Articles 2018 05 1805lfw Nb F1
    Fiber Optics

    Hollow-core fibers deliver ultraviolet light without solar degradation

    Gail Overton
    May 1, 2018
    A single-mode antiresonant hollow-core fiber design offers less than 1 dB/m transmission for the same UV wavelengths, but with no observed solar degradation after 1 hour when ...
    Content Dam Lfw Print Articles 2018 05 1805lfw Nb F3
    Optics

    Metamaterial lens has numerical aperture of 0.99

    John Wallace
    May 1, 2018
    A flat metamaterial lens with a thickness of a third of a wavelength and an NA of 0.99 at a 715 nm wavelength has been created.
    Conard Holton2
    Detectors & Imaging

    Innovations in photonics, duly noted

    Conard Holton
    May 1, 2018
    The Innovators Awards program gives us the pleasure of recognizing more innovations in photonics by broadening the scope of honorees and noting many important advances that might...
    Content Dam Lfw En Articles Print Volume 54 Issue 05 Features Laser Focus World Announces 2018 Innovators Awards Leftcolumn Article Thumbnailimage File
    Positioning, Support & Accessories

    Laser Focus World announces 2018 Innovators Awards

    May 1, 2018
    For the first time, Laser Focus World has held its Innovators Awards program, which celebrates the disparate and innovative technologies, products, and systems found in the photonics...
    FIGURE 1. With five axes of computer-controlled motion, UltraForm Finishing (UFF) is capable of polishing aspheric and freeform surfaces.
    Optics

    Optical Manufacturing: Polishing aspheres: Spanning the scale of material hardness

    Pat Bechtold
    May 1, 2018
    From soft optical glasses to hard technical ceramics, flexible technology enables efficient polishing of aspheric surfaces to submicron form accuracies.
    FIGURE 1. Photonic crystal fiber (PCF) designs proposed to reduce transmission loss of electromagnetic (and especially terahertz) waves include a hybrid core in a regular hexagonal cladding (a), a hybrid core in a modified hexagonal cladding (b), a rotated hexagonal core in a circular cladding (c), and a diamond-shaped core in a kagome cladding (d).
    Fiber Optics

    Photonic Crystal Fibers: Porous-core photonic crystal fibers guide polarization-preserving terahertz waves

    May 1, 2018
    Highly birefringent and near-zero-dispersion-flattened photonic crystal fibers guide terahertz waves for applications in low-loss imaging and sensing.
    Susan Reiss 720
    Spectroscopy

    Business Forum: International Brain Initiative bodes well for bio-optics

    Susan Reiss
    May 1, 2018
    The Canberra Declaration to create the Initiative promises to further heighten the profile of brain research—and biophotonics tools that enable it.