Two-level atoms moving in strong biharmonic and monochromatic counterpropagating fields

The polarization and power spectra of radiation of two-level atoms moving in a field of biharmonic and monochromatic counterpropagating waves are computer simulated. It is shown that, as the frequencies of the counterpropagating waves are scanned with respect to the central frequency of the Doppler contour in the intensity distribution of groups of atoms moving at velocities that satisfy the resonance conditions for multiphoton transitions between quasi-energy levels, apart from well-known sub-Doppler resonances, narrow peaks appear. Such resonances should also occur for the stimulated light pressure force.