Patent ID: 6064630
Filing Date: 2000-05-16
Classification: G01L

Abstract:
A system for sensing changes in a value of an environmental parameter, comprising:a coherent optical signal source;an interferometer optically coupled to the optical source to receive a pulsed optical signal therefrom, the interferometer includinga first optical coupler splitting the optical signal into first and second beams;the first and second beams traversing first and second optical legs, respectively, wherein an optical path length through one of the optical legs is longer than an optical path length through the other optical leg;a first mirror terminating the first optical leg to reflect the first beam back into the first optical leg;a proof mass suspended on a frame in a cavity including a fluid, wherein the proof mass is movable in response to a change in the value of the parameter, the proof mass further including a reflective surface forming a second mirror, wherein the second mirror terminating the second optical leg to reflect the second beam back into the second optical leg;a second optical coupler recombining the first and second beams after their reflection back along their respective optical legs by the first and second mirrors to form an interference pattern;an optical detector responsive to the interference pattern, and generating an electrical signal indicative of the value of the interference pattern; anda processor responsive to the electrical signal, correlating a change in the value of the interference signal with a change in the value of the parameter.