Nonlinear interaction of opposite waves in a ring helium—neon laser with illumination of the active element

Theoretical and experimental investigations were made of a light-induced nonreciprocity of a single-mode ring He–Ne laser with the active element illuminated by a traveling wave generated in a linear He–Ne laser utilizing the same transition (λ = 1.15μ). The theoretical analysis was made using a vector semiclassical theory of three interacting waves with arbitrary polarization states. The dependences of the intensities and the difference between the frequencies of the opposite waves on the tuning of the linear laser were observed experimentally. The theoretical and experimental results were in satisfactory agreement. The feasibility of practical utilization of this effect was considered.