Briefs: Electronics & Computers

Traveling-Wave Photomixer With Angle-Tuned Phase Matching

An experimental traveling-wave photomixing device generates narrow-band electromagnetic radiation at frequencies up to a few terahertz. The device is, potentially, a prototype of...

Briefs: Photonics/Optics

Holographic Circle-to-Point Converter

The figure schematically depicts the use of a special-purpose holographic plate to focus light from (1) circular interference fringes generated by a Fabry-Perot etalon to (2) a series of points, each...

Briefs: Photonics/Optics

Compact, Low-Power, Low-Voltage Laser Ignition System

A prototype laser ignition system has been developed for use in a hydrogen/oxygen-burning spacecraft thruster. The system could readily be adapted to terrestrial applications in which...

Briefs: Photonics/Optics

Using Laser Rangefinders To Align Two Structures

An optoelectronic system provides information on the relative position and orientation of two structures that are required to be brought together slowly and gently in a prescribed alignment....

Briefs: Photonics/Optics

Designing for Optimum Response in a Pushbroom Spectrometer

A method of designing a compact pushbroom imaging spectrometer includes explicit consideration and minimization of nonuniformity of spatial and spectral response. It appears that...

Briefs: Photonics/Optics

Laser-Induced Rotation of a Levitated Sample in a Vacuum

A high-power laser beam can be used to apply a torque to a sample of material that is electromagnetically and/or electrostatically levitated in a vacuum. The torque can be used to...

Briefs: Photonics/Optics

Tailoring Cores of Optical Fibers by a Sol-Gel Method

A method of tailoring the cores of optical fibers to obtain optical properties needed for specific photonic applications exploits the sol-gel process. The method is expected to open new...

Briefs: Photonics/Optics

Optical Surfaces Based on Arrays of Microscopic Pillars

Surfaces would be textured with dense arrays of pillars characterized by micron and submicron dimensions, according to a proposal, in order to impart desired optical properties to the...

Briefs: Photonics/Optics

Nonvolatile Holographic Storage in Doubly Doped LiNbO₃

Recent research has demonstrated the feasibility of an all-optical method of recording and readout of holograms in photorefractive crystals, with capabilities for both nonvolatile...

Briefs: Electronics & Computers

The KSC Simulation System

The Kennedy Space Center (KSC) Simulation System is a computing system capable of large-scale mathematical modeling for real-time simulation of the behavior of a complex system that could include many different...

Briefs: Information Technology

Digital Library of NACA Reports

The NACA Technical Report Server (NACATRS) is both a node in the NASA Technical Report Server and a stand-alone World Wide Web (WWW) site. The NACATRS is dedicated to the preservation and dissemination of...

Briefs: Information Technology

Finding Known Shapes in an Image by Pruning Parameter Space

An improved method of processing two- and three-dimensional image data to locate known shapes called "geometric primitives" involves (1) extraction of edges and other relevant image...

Briefs: Physical Sciences

Improved Infrared Imaging of Bulk Defects in CdZnTe Wafers

An improved method of infrared imaging of bulk defects in cadmium zinc telluride (CdZnTe) wafers has been developed. The method is intended primarily to be a means of identifying...

Briefs: Physical Sciences

Image Generators With Compact Optics

Compact image generators that contain illumination sources and electronically controlled spatial light modulators have been invented. Compactness is achieved by folding of the optical paths that link the...

Briefs: Physical Sciences

Hand-Held Instrument for Imaging Hydrogen Fires

A hand-held instrument that contains two silicon-based charge-coupled-device (CCD) video cameras (see figure) has been developed for imaging hydrogen fires. This or a similar instrument is...

Briefs: Physical Sciences

Improvements in Computed-Tomography Imaging Spectrometry

Two major improvements, described below, have been made in the construction and operation of a computed-tomography imaging spectrometer (CTIS). These plus future improvements can be...

Briefs: Electronics & Computers

GA Synthesis of Circuits Using a Linear Representation

A method of automated synthesis of electronic circuits involves the use of a linear (as defined below) genome representation of circuit elements and of connections among them, plus a...

Briefs: Electronics & Computers

Silicon Carbide npnp Thyristors

Thyristors (semiconductor controlled rectifiers) made from silicon carbide have been fabricated and tested as prototypes of power-switching devices capable of operating at temperatures up to 350 °C. The...

Briefs: Test & Measurement

Improved Methods of Testing Cryogenic Insulation Materials

Two improved methods have been developed for testing continuously rolled blankets and blanketlike thermal-insulation materials typically used in cryogenic vacuum systems. Both...