Direct static-strain measurement utilizing signal fading and spectrum analysis in a fiber optic interferometric sensor

摘要

Abstract: A highly accurate linear method of static phase shift measurement based on the concurrent utilization of signal fading, a tan$+$MIN@1$/ algorithm and photovoltage spectrum analysis in a fiber optic interferometric strain sensor is presented. The static phase shift is superimposed on a controlled dynamic phase modulation derived from an optical phase modulator in one arm of the interferometer. Good agreement is demonstrated between the phase shift obtained through experiment and that from the theoretical analysis based on 1/f noise. This detection scheme has wide applications to static and dynamic phase shift measurements in fiber optic interferometric sensors used in several smart structure configurations. !12