Vibration-displacement measurements with a highly stabilised optical fiber Michelson interferometer system

摘要

A highly stabilised vibration-displacement measurement system, which employs fiber Bragg gratings(FBGs) to interleave two fiber Michelson interferometers that share the common-interferometric-optical path, is presented. The phase change in the interferometric signals of the two fiber Michelsoninterferometers have been tracked, respectively, with two electronic feedback loops. One of the fiberinterferometers is used to stabilise the system by the use of an electronic feedback loop to compensatethe environmental disturbances. The second fiber interferometer is used to perform the measurementtask and employs another electronic feedback loop to track the phase change in the interferometricsignal. The measurement system is able to measure vibration-displacement and provide the sense ofdirection of the displacement. The frequency range of the measured vibration-displacement is from 0.1to 200 Hz and the measurement resolution is 10 nm.