Dual-polarization interferometric fiber-optic gyroscope with an ultra-simple configuration

We demonstrate a novel dual-polarization interferometric fiber-optic gyroscope (IFOG), which needs only one coupler and no polarizer. Polarization nonreciprocity (PN) errors in common IFOGs will increase significantly if the polarizer is absent, or if only one coupler is used. In our setup, however, PN errors are effectively compensated by using two balanced polarizations. The 2 km coil, open-loop configuration obtains a bias instability of 0.02°/h in detecting the Earth’s rotation rate. Its performance difference from the conventional two-coupler IFOG is only a stable bias, caused by coupler nonreciprocity.