Tech Briefs

Bare Fiber Holder Eases Positioning for Optical Measurements

Measurements are accurate and repeatable from device to device and user to user. Bare fiber measurements are common in optical component manufacturing before the device under test (DUT) is connectorized and final tested. Insertion loss and polarization dependent loss are typical measurements on passive components before they are connectorized. The precision of these measurements is high, on the order of ±0.01 dB, and repeatability of the measurements is critical in determining the ultimate throughput of the process and devices. With small fiber cores, 8 to 62.5 μm, handling bare fiber for measurements is difficult because the fiber core is easily susceptible to breakage.

Posted in: Physical Sciences, Photonics, Briefs

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Miniature Dual-Wavelength Camera Using InGaAs Focal Plane Arrays

Camera simultaneously images visible and shortwave infrared light.The recent development of indium gallium arsenide (InGaAs) focal plane arrays (FPAs) capable of imaging visible and shortwave infrared (SWIR) wavelengths has yielded a miniature dualwavelength camera with no moving parts that weighs only 11 ounces, consumes less than 1.6 W of power, and operates at room temperature.

Posted in: Physical Sciences, Photonics, Briefs

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Two-Photon Fluorescence Microscope for Microgravity Research

The benefits of two-photon fluorescence microscopy are realized at reduced cost. A two-photon fluorescence microscope has been developed for the study of biophysical phenomena. Two-photon microscopy is a novel form of laser-based scanning microscopy that enables threedimensional imaging without many of the problems inherent in confocal microscopy. Unlike one-photon optical microscopy, two-photon microscopy utilizes the simultaneous nonlinear absorption of two near-infrared photons. However, the efficiency of two-photon absorption is much lower than that of one-photon absorption, so an ultra-fast pulsed laser source is typically employed.

Posted in: Physical Sciences, Photonics, Briefs

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Tissue Engineering Using Transfected Growth-Factor Genes

Cells, matrices, and bioreactors are tailored to promote functional tissue engineering of cartilage. A method of growing bioengineered tissues includes, as a major component, the use of mammalian cells that have been transfected with genes for secretion of regulator and growth-factor substances. In a typical application, one either seeds the cells onto an artificial matrix made of a synthetic or natural biocompatible material, or else one cultures the cells until they secrete a desired amount of an extracellular matrix. If such a bioengineered tissue construct is to be used for surgical replacement of injured tissue, then the cells should preferably be the patient’s own cells or, if not, at least cells matched to the patient’s cells according to a human-leucocyte-antigen (HLA) test. The bioengineered tissue construct is typically implanted in the patient’s injured natural tissue, wherein the growth-factor genes enhance metabolic functions that promote the in vitro development of functional tissue constructs and their integration with native tissues. If the matrix is biodegradable, then one of the results of metabolism could be absorption of the matrix and replacement of the matrix with tissue formed at least partly by the transfected cells.

Posted in: Medical, Briefs

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Articulating Support for Horizontal Resistive Exercise

Supports can be optimized for a variety of prescribed exercises. A versatile mechanical device provides support for a user engaged in any of a variety of resistive exercises in a substantially horizontal orientation. The unique features and versatility of the device promise to be useful in bed-rest studies, rehabilitation, and specialized strength training. The device affords a capability for selectively loading and unloading of portions of the user’s body through its support mechanisms, so that specific parts of the body can be trained with little or no effect on other parts that may be disabled or in the process of recovery from injury. Thus, the device is ideal for rehabilitation exercise programs prescribed by physicians and physical therapists. The capability for selective loading and support also offers potential benefits to strength and conditioning trainers and athletes who wish to selectively strengthen selected parts.

Posted in: Medical, Briefs

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Automation of Vapor-Diffusion Growth of Protein Crystals

High-throughput experiments are accelerated through automation of routine operations.Some improvements have been made in a system of laboratory equipment developed previously for studying the crystallization of proteins from solution by use of dynamically controlled flows of dry gas. The improvements involve mainly (1) automation of dispensing of liquids for starting experiments, (2) automatic control of drying of protein solutions during the experiments, and (3) provision for automated acquisition of video images for monitoring experiments in progress and for post-experiment analysis.

Posted in: Medical, Briefs

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Organic Light-Emitting Diode Displays for High-End Audio Systems

OLEDs improve resolution, definition, and user ergonomics.Organic light-emitting diode (OLED) technology comprises organic thin films that, when placed between two conductors, can serve as a display. This technology requires very little power and produces radiant, self-luminous displays that do not require backlighting, resulting in thin, very compact displays. Furthermore, they offer crystal clear resolution in any lighting environment.

Posted in: Physical Sciences, Photonics, Briefs

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