DISPERSION OF A THREE-LEVEL QUANTUM SYSTEM IN A BICHROMATIC FIELD
We have considired some aspects of interaction of a V-type quantum system with the bichromatic field of two waves, one of which is assumed to be weak. The dynamics is traced of splitting of spectral contours of the absorption (amplification) coefficient of the signal wave into separate components. An effect of amplification of the signal wave is discussed which occurs in its frequency-degenerate two-wave interaction with a pumping while tuning the field frequency to the point of zero dispersion. Conditions are determined which are imposed on the concentration of resonant atoms and spectral regions of frequencies of interacting waves, whereby for the correct description of the effects under consideration, it is necessary to allow for the action of the pumping and signal in both dipole-allowed transitions of an ensemble of three-level systems of V-type. The results are presented of calculating the imaginary and real parts of the susceptibility of a resonant medium at the signal wave frequency, depending on the parameters of powerful radiation and resonant transitions of the V-system.