Investigation of the parameters of laser radiation emitted by a single-frequency high-power gas laser

Studies to determine whether it is possible to obtain a stable single-frequency mode of generation in large He–Ne lasers were undertaken. Selection of the frequencies in the particular lasers was performed by means of a Fabry–Perot interferometer situated at a low angle to the axis of the cavity resonator. It is shown that a laser that has been converted to function in a single-frequency mode of emission assures a coherence length of at least 10 m even when subjected to technical vibratory and acoustic effects.