Patent ID: 6154308
Filing Date: 2000-11-28
Classification: G01D

Abstract:
A method for demodulating signals output from a sensor array that includes a plurality of pathlength mismatched interferometers to determine phase shifts in optical signals that have propagated through the interferometers, comprising the steps of:providing an optical signal;modulating the phase of the optical signal;inputting the modulated optical signal to the sensor array;controlling the ramp voltage to generate two different phase steps in sequence within a time interval T in signals output from the interferometer;producing a first output signal S.sub.1 that is a function of the phase shift .phi. and a first one of the phase steps in a first portion of the time interval T;producing a second output signal S.sub.2 that is a function of the phase shift .phi. and the other one of the phase steps in a second portion of the time interval T; andprocessing the signals S.sub.1 and S.sub.2, to calculate the phase shift .phi. as functions of the sum and differences of the signals S.sub.1 and S.sub.2.