Fiber interferometric sensor and phase compensation method of PGC demodulator

摘要

A fiber interferometric sensor (300) including a light source (310), at least one fiber interferometer (320), at least one optical receiver (330), and at least one PGC demodulator (340) having a phase compensation function is provided. The fiber interferometer (320) is coupled to the light source (310) for outputting an optical interference signal according to the sensed variation of physical fields. The optical receiver (330) is coupled to the fiber interferometer (320) for converting the optical interference signal into an electrical signal. The PGC demodulator (340) is coupled to the optical receiver (330) for demodulating the electrical signal to obtain a sensing phase signal. The PGC demodulator (340) has a processing unit (342) and two phase compensators (344, 346). The processing unit (342) is suitable for creating a fundamental carrier and a second harmonic carrier to demodulating the electrical signal. The phase compensators (344, 346) are suitable for respectively compensating a first phase angle for the fundamental carrier and a second phase angle for the second harmonic carrier.