Influence of combination tones on the radiation intensity of a two-mode gas laser

For the first time, a theoretical and experimental analysis has been made of the contribution of combination tones to the instability of radiation from a two-mode gas laser. It was found that these tones resulted in regular oscillations of the mode intensities at twice the intermode beat frequency. The level of these oscillations and the law governing the behavior of their amplitude were determined as a function of various operational parameters in a two-mode He–Ne laser (λ = 3.3922 μm).