Effect of Diffraction Nonreciprocity in a Laser Gyro

Physical effects that lead to zero shift of a laser gyro (LG) are considered. It is shown that under severe thermal and mechanical deformations, the main source of zero shift is the effect of diffraction nonreciprocity. Diffraction at ring cavity apertures, combined with nonlinear polarizability of the active medium, causes a difference in the frequencies of the counter-propagating waves. The results of model experiments presented in this paper have made it possible to identify the magnitude of deformations and LG zero drift resulting from the diffraction effect.