The efficiency of parametric multiphoton frequency conversion in a stochastic pumping field

An analysis is presented of resonant parametric frequency conversion during the multiphoton excitation of two-level atoms in a random field, modulated in phase and amplitude by a Markov process. The k-harmonic intensity is investigated as a function of the intensity and spectral width of the pumping field. It is shown that the resonant frequency conversion in a random amplitude-modulated field is more efficient than under monochromatic excitation. The generation of ultrashort tunable pulses in a stochastic pumping field is also examined.