Accession Number : ADD006627

Title :   Endless Fiber Interferometer Rotary Motion Sensor.

Descriptive Note : Patent,


Personal Author(s) : Redman,Charles M

Report Date : 09 Jan 1979

Pagination or Media Count : 6

Abstract : A rotary motion sensor which employs an endless, closed-loop, multiple turn fiber interferometer. Coherent laser radiation is coupled into the fiber interferometer in both a clockwise and counter-clockwise direction and is permitted to traverse the entire interferometer waveguide many times so as to increase the cumulative phase shift due to multiple traversal. Means are provided for coupling the coherent radiation into and out of the fiber interferometer. Means are also provided for generating a pair of reference optical signals which are heterodyned with the extracted clockwise and counter-clockwise signals to produce a pair of beat frequency signals at manageable, acoustic frequencies. The relative cumulative phase shift between the output acoustic signals and the circulating signals are the same so as to provide an extremely precise measurement of the rate of rotation. In a preferred embodiment, the coupling means as well as the reference signal generating means comprise an acoustic waveguide for generating an acousto-optic grating across the paths of the coherent optical signal and the fiber interferometer. (Author)

Descriptors :   *Patents, *Angular motion, *Optical detection, Laser beams, Interferometry, Phase shift, Fiber optics, Optical waveguides, Coherent radiation, Heterodyning, Acoustooptics

Subject Categories : Test Facilities, Equipment and Methods
      Optical Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE