Four-photon processes stimulated by a fluctuating pump

Four-photon parametric light amplification stimulated by noisy pump in a dispersive medium, is theoretically analyzed. The model of the fluctuating phase is used. The increments in case of temporal as well as of spatial laser pump modulation are considered. It is shown that the efficiency of the four-photon process due to a broad-band pump is comparable to that of monochromatic pump. Quantitative estimates for the medium of metal vapor are given, too.