Distributed Measurement of Polarization Characteristics for a Multifunctional Integrated Optical Chip: A Review

Multifunctional integrated optical chip (MFIOC) has the function of phase modulation, beam split, and polarization rejection, thus is widely used in fiber-optic sensing, in particular, the interferometric fiber-optic gyroscope (IFOG). In this paper, we reviewed the distributed measurement of polarization characteristics for an MFIOC, including the measurement principle based on the optical coherence domain polarimetry (OCDP), the modeling methods based on the Jones matrix and optical path, and the measurement performance. Also, the system errors that result from the optical delay line in the OCDP instrument or the birefringence dispersion in the MFIOC, the relevant suppression techniques, and the calibration technique are discussed. The technique meets the measurement requirement of MFIOC that with the polarization extinction ratio of more than 80 dB. Such MFIOC is the key component of the IFOG that with the strategic-grade performance.