Optimized Design on Polarization Maintaining Photonic Crystal Fiber for Higher Precision FOGs

We propose a single mode polarization maintaining photonic crystal fiber (PM-PCF) with small coating diameter for higher precision fiber optic gyroscopes (FOGs) in order to solve the nonreciprocity problem caused by higher order modes transmitted in previous PM-PCF. To obtain the optimized fiber structure parameter region, the dependences of the PM-PCF properties including modal field distribution, birefringence, and confinement loss on the normalized frequency, the enlarged air hole diameter and air filling ratio are numerically analyzed by using the full vector finite element method. Taking the characteristics of PANDA PMFs as a reference, the optimized parameter region is achieved. A FOG made with the 1500 m optimized PM-PCF coil is built and tested. The static and full temperature bias stabilities of are better than 0.005 deg/h and 0.008 deg/h respectively, which illustrates that the optimized PM-PCF is suitable for higher precisions FOGs.