Parametric nonlinear supernarrow resonances in the susceptibility spectrum of a three-level atomic system in multimode strong radiation at the main transition and the weak biharmonic probe field

Summary form only given, as follows. One of the leading directions of nonlinear laser spectroscopy is a study of interaction of radiation with material. The purpose of the work is to research effects of amplification of radiation without creation of initial inversion of population levels in three-level atomic media. Calculation of generation parameters in three-level systems on the main transition will allow to get a generation at frequencies where creating the usual lasers is difficult (ultraviolet and X-ray area).