Photonics

A rugged laser-diode oxygen sensor is being developed for detecting leaks of oxygen from diverse systems, including rocket engines, cryogenic systems, and medical equipment. The sensor is required to have a range of 250 to 250,000 parts per million, to be accurate within 5 percent, to be capable of operating at any...

A method of characterization of growing of protein crystals involves the utilization of an optical imaging technique known as spatial phase imaging. The methods used heretofore have been, variously, invasive (e.g., adding a dye that is absorbed by the protein of interest), destructive (e.g.,...

A proposed infrared transmitting fiber-optic endoscope, which would partly resemble a visible-light fiber-optic endoscope, instrument could be used to perform thermal imaging in harsh environments and/or confined spaces in a variety of situations in aerospace, industrial, automotive, and medical settings.

A compact instrument includes a fiber-optic probe that utilizes the evanescent-wave interaction to measure the accumulation of a biofilm. This instrument is a prototype of instruments that could be used to effect continuous monitoring and provide early warning of biofilms associated with...

Liquid-level-measuring systems based on fiber-optics are under development as compact, lightweight alternatives to systems based on float gauges and other conventional sensors. For liquids that pose explosion hazards, fiber-optic sensors are inherently safer because they do not include electrical connections inside...

A developmental instrumentation system rapidly acquires full Raman spectra of gas molecules. The system is based on the principle of multiplex coherent antistokes Raman spectroscopy (CARS) and incorporates improvements over prior multiplex CARS systems. Among the potential applications for systems...

Profile refractometry is a laser-based technique for measuring the index of refraction of a fluid as a function of time and position in a fluid. The technique was developed for use in quantifying the Soret effect in a binary fluid subject to an applied thermal gradient. (The Soret effect is the...

A technique for Fourier synthesis of optical pulses involves radio-frequency (RF) phase modulation of laser beams, Brillouin selective amplification of modulation sidebands, and, finally, generation of pulses through coherent superposition of (and thus interference among) the sidebands....

Generalized Timelines API is a computer program that provides (1) a means of representing arbitrary realworld state and resource information for use in planning, scheduling, and plan- and schedule-executing software and (2) an application-programming interface (API) that accelerates the...

A process for the fabrication of coated sapphire multimode optical fibers has been developed. Sapphire multimode optical fibers are suitable for use as embedded sensors for measuring mechanical and thermal stresses and strains in material specimens at temperatures up to about 1,500 °C.