On the basis of spatio-temporal numerical model the non-stationary manifestation conditions in frequency-modulated cw laser beam propagating in resonance conditions are investigated. Generation of subharmonic and optical frequency division are observed and analyzed in conditions of cw laser beam resonance self-action.
Periodical modulation of frequency, typical for spectroscopic purposes, is numerically modelled in transversely limited, propagated through a saturable two-level absorber cw laser beams. At modulation periods comparable with the atomic relaxation times the time and frequency dependence of the output intensity exhibits the manifestations of delayed medium response, including time-dependent lens and aperture effects that may be of importance in spectroscopy. Simultaneous manifestation and interaction of resonant self-action and non-stationary transients are analyzed in present work.