<title>A Passive Accurate Phase-Measurement System For A Fiber Optic Interferometer</title>

Abstract

A passive interferometric demodulation technique is described and experimentally demonstrated.This technique uses a piezo -electrically stretched coiled fiber as a phase shifter to drive the interferometer into two states with a 90° phase difference between them.The method exhibits good linearity, high sensitivity, and the potential for large dynamic range.The demodulation technique eliminates the phase tracker resetting problem encountered in active homodyne detection schemes.