Photonics/​Optics

Briefs: Photonics/Optics

Etching Mirror Facets on SOI Optical Waveguides

A process that would include a combination of dry and wet chemical etching has been proposed for making facets for low-loss mirrors on silicon-on-insulator (SOI) optical waveguides....

Briefs: Photonics/Optics

Two-Fiber-Optic Method of Laser Doppler Velocimetry

The figure depicts the basic optical layouts for (1) conventional laser Doppler velocimetry (LDV) and (2) a newer method of LDV based partly on the use of two optical fibers. Whereas...

Briefs: Photonics/Optics

Arrays of QWIPs With Spatial Separation of Multiple Colors

Focal-plane arrays of quantum-well infrared photodetectors (QWIPs) featuring adjacent pixels sensitive to different colors have been proposed. An array of this type would make it...

Briefs: Photonics/Optics

Making Three-Dimensional Holograms Visible From All Sides

A technique for projecting holographic images to make both still and moving three-dimensional displays is undergoing development. Unlike older techniques based on stereoscopy to give...

Briefs: Photonics/Optics

Adaptive Multiplexing for Free-Space Optical Communication

"Laser-based adaptive wavelength division multiplexing and code division multiplexing" (LAWDM-CDM) is the name of a method that has been proposed to increase security,...

Briefs: Photonics/Optics

Magnetically Suspended Optical Chopper Wheel

A magnetically suspended, motor-driven light-chopping wheel has been developed as an alternative to a traditional light-chopping wheel suspended on ball bearings. This chopper (see figure) is...

Briefs: Photonics/Optics

Fiber-Optic Rotary Joint for Passing High-Definition Video

A video camera has been integrated with a tracking pedestal (see figure) for tracking of aircraft and spacecraft. The camera is of a high-definition (1,280 × 720 pixels),...

Briefs: Photonics/Optics

Mesoscopic Steerable Mirror

A proposed lightweight, micromachined, multiaxis-steerable mirror would have mesoscopic dimensions. Its steering function would involve mesoscopic positional excursions of its support points and would be...

Briefs: Photonics/Optics

Testing Grazing-Incidence Mirrors at Nearly Normal Incidence

An optical system that utilizes visible light at nearly perpendicular incidence has been invented for use in testing the surface figures of nominally axisymmetric (paraboloidal,...

Briefs: Photonics/Optics

Phase-Retrieval Camera for Optical Testing

A portable instrument denoted a phase-retrieval camera (PRC) is designed to enable the testing of large, lightweight optics in the presence of vibrations and atmospheric turbulence. The development...

Briefs: Photonics/Optics

Liquid-Crystal Phase-Shifting Shearing Interferometer

The liquid-crystal phase-shifting shearing interferometer is a common-path interferometer based partly on a lateral-shear-plate interferometer. It bears a partial similarity to the...

Briefs: Photonics/Optics

Fiber-Optic Phase-Locked Loop Sensitive to Local Strain Only

The figure schematically depicts an apparatus for measuring strain at only one designated location on a structure. The apparatus is a fiber-optic phase-locked loop, wherein strain...

Briefs: Photonics/Optics

Light Recycling and Color Scrolling for Brighter Displays

The efficiencies and thus the brightnesses of flat-panel projectors based on liquid-crystal devices (LCDs) and digital mirror devices (DMDs) would be increased by the combination of...

Briefs: Motion Control

Compact, Stiff, Lightweight, Quick-Release Clamp

The term "COSMOWRAP" denotes a compact, stiff, remotely actuatable, lightweight, quick-release clamp that could be substituted for the larger, heavier, and more-difficult-to-use toggle-action...

Briefs: Photonics/Optics

Crystalline Organic Films for Optical Applications

Cells that contain thin, single-crystal films of photoresponsive organic materials [e.g., meta-nitroaniline (m-NA)] have been invented for use as nonlinear optics and especially as...

Briefs: Photonics/Optics

Optoelectronic Oscillator With Low Acceleration Sensitivity

An optoelectronic oscillator with a nominal operating frequency of 11.763 GHz has been designed and constructed to demonstrate a technique for reducing the sensitivity of the...

Briefs: Photonics/Optics

Apparatus Measures X-Ray Diffraction and Fluorescence

The figure depicts an apparatus for measuring x-ray diffraction (XRD) and/or x-ray fluorescence (XRF) in a specimen of material. The specimen could be, for example, a standard XRD powder...

Briefs: Photonics/Optics

Fluorescent Dyes for Two-Photon Microscopy

A proposed program of research would be oriented toward the development of fluorescent dyes for use in two-photon microscopy. Two-photon microscopy and its predecessor, one-photon microscopy, are...

Briefs: Photonics/Optics

Critical Composition Buffering for Growing InxGa1-xAs on InP

A method of growing lattice-mismatched In_xGa_1-xAs epitaxial layers on InP substrates using intermediate buffer layers of...

Briefs: Photonics/Optics

Portable Airborne Multispectral-Imaging System

A portable instrumentation system that includes an airborne and a ground-based subsystem acquires multispectral image data over swaths of terrain ranging in width from about 1/2 to 1 km. The...

Briefs: Electronics & Computers

Lossless Image-Compression Algorithm Implemented in an FPGA

A lossless image-compression algorithm that can be executed entirely in electronic hardware has been developed. This algorithm yields about 15 percent more compression than does the...

Briefs: Photonics/Optics

Hardware and Software for Air-to-Air Schlieren Imaging

Software and electronic hardware are being developed to provide cockpit guidance and camera control for an air-to-air schlieren photography system that is to be used to take...

Briefs: Photonics/Optics

Lateral-Current-Collection HgCdTe Infrared Detectors

Arrays of HgCdTe infrared photodetectors have been developed to satisfy stringent performance requirements for use in NASA’s Tropospheric Emission Spectrometer. The design of these...