Resonances in the spectral density of the frequency distribution of radiation emitted from a laser with nonlinear absorption

A description is given of a method for obtaining narrow resonances of the spectral density of the radiation emitted from a gas laser with nonlinear absorption. The main properties of these resonances are discussed from the point of view of their use in very-high-resolution spectroscopy of low-pressure gases and in laser frequency stabilization. Resonances in the spectrum of the radiation emitted from a He–Ne laser with a methane absorber are reported. A resonance of this kind is used to stabilize the emission frequency of this laser.