Laser strapdown inertial navigation system has become the mainstream of the medium and high precision inertial navigation systems, and its core component is a laser gyro (LG) [20,23].The LG have the advantages of high precision, large dynamic range, fast starting, super stable scale factor, strong environmental adaptability, high reliability and long working life [1,13,18].Apart from Russia, only four countriesthe United States, France, China and Israelhave been able to master the complex knowledge-intensive technology of laser gyros production [13,23,24].Even though the new types of gyros appeared, but the LGs still keep the highest market share and are largely used in navigation and guidance systems. As it is seen in Fig. 1 [24], LGs occupy the highest accuracy zone with bias instability about 0.01 °/h and much less.