Accession Number : ADD013788

Title :   Fiber Optical Time Delay Resonant Oscillating Strain Gauge.

Descriptive Note : Patent, Filed 13 Aug 86, patented 16 Feb 88,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Brininstool, Michael R ; Garcia, Graham A

Report Date : 16 Feb 1988

Pagination or Media Count : 7

Abstract : Longitudinal tensile and/or compressive strain in optical fibers is determined by an entirely optical technique. A test optical fiber optically coupled to optical injection and extraction couplers form an optically recirculating loop. A semiconductor laser diode feeds a series of narrow light pulses into the loop via the injection coupler and an oscilloscope or signal peak detector give usual indications of optical correlation when an avalanche photodiode provides responsive signals coming from the extraction coupler. Straining the optical test fiber will change the loop's length and, hence, the time delay between reoccurring pulses so that the loop frequency of the narrow optical pulses must be correspondingly changed to provide maximum signal correlation.

Descriptors :   *EXTRACTION, *INJECTION, *OPTICAL CORRELATORS, *OPTICAL DETECTORS, *TEST EQUIPMENT, AVALANCHE DIODES, CORRELATION, COUPLERS, DELAY, DETECTORS, FEEDING, FIBER OPTICS, FREQUENCY, LENGTH, LIGHT PULSES, LOOPS, OPTICAL PROPERTIES, OPTICS, PEAK VALUES, SEMICONDUCTOR DIODES, SEMICONDUCTOR LASERS, SIGNALS, TIME INTERVALS, PATENTS

Subject Categories : Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE