Output Properties of Dual-Polarization IFOGs

In the optically compensated dual-polarization IFOG, absolute reciprocity is not required, as the nonreciprocal error is eliminated by the compensation method. One of its special features is that the nonreciprocal port and reciprocal port are theoretically similar, both of which have polarization error compensation mechanism and can obtain stable angular velocity output. Therefore, two possible beneficial designs are available: One is two-port detection, and the two signals can be processed jointly by proper two-channel algorisms for further noise reduction; Another application is to achieve a single-coupler IFOG, with a very simple structure and very low cost to achieve stable performance. In this chapter, we first demonstrate the feasibility of the nonreciprocal port in the dual-polarization IFOG, and then experimentally verify the two-port IFOG and the single-coupler IFOG, respectively