Nonlinear optical effects in a pumping field with a diffusing phase

A theoretical analysis is given of the Raman and parametric interactions in a pumping field whose phase diffuses with time. Equations are obtained for and values are calculated of steady-state and transient increments of the average fields and intensities of light waves. An analysis is made of the dependences of these increments on the width of the pumping radiation line, detuning of the group velocites, and other parameters which govern the efficiency of nonlinear conversion.