利用光纤3×3耦合器和光纤光栅构成能有效补偿环境干扰的光纤干涉振动测量系统。该测量系统包含干涉臂几乎重合的两个光纤迈克耳孙干涉仪,其中一个光纤迈克耳孙干涉仪利用一个电子反馈环节补偿环境干扰对测量系统的影响,以提高系统的测量精度;另一个光纤迈克耳孙干涉仪利用另一个电子反馈环节跟踪由于振动引起的相位变化,从而实现对振动幅值的测量及振动方向的确定。结果表明,该系统可对频率为0.1-200 Hz的振动进行测量,测量灵敏度为6 μm/V。

A highly stabilized fiber 3×3 coupler Michelson interferometer vibration measurement system,which employs fiber Bragg gratings to interleave two fiber Michelson interferometers that share the common interferometric-optical-path,is presented. One interferometer uses an electronic feedback loop to compensate for the low frequency drift in the phase of the interferometric signal which is resulted from environmental disturbances,while the other one uses another electronic feedback loop to track the phase variation induced by the measured vibration,and thus the amplitude measurement of the vibration and the vibration direction are measured simultaneously. The results show that the measurement system is designed to be capable of measurement vibration with frequencies ranging from 0.1 Hz to 200 Hz and the measurement sensitivity is 6 μm/V.