Stabilization of the oscillation frequency of a gas laser by comparison with a radio-frequency standard

An investigation was made of the dependence of the mode separation on various parameters of a laser operating at λ = 0.63 μ and emitting two or three axial modes. Certain properties of the frequency characteristics were used for the stabilization of the gas-laser emission by comparing the mode separation with a radio-frequency standard. The experimental results obtained in the emission of three axial modes in the region of their symmetrical tuning were analyzed theoretically. It was found that a stabilized gas laser could have a long-term frequency stability better than any published value. The absolute frequency stability of such a laser (characterized by a high relative stability over long periods) would be determined by the drift of the center of an atomic-transition line as a result of various factors.