Statistical and coherence effects in nonlinear optical parametric up conversion. II. Incoherent interaction

Parametric up conversion (PUC) by incoherent nonlinear optical mixing of second-order coherent strong pumping radiation and another weak chaotic input radiation with a finite spectral width is treated in the second part of this paper. The efficiency of PUC is calculated in the second approximation of the iterative method. It is shown that in the case of perfect phase matching the efficiency of PUC decreases with increase of both the spectral width of the input radiation and the dispersion of medium, whilst at considerable values of phase mismatch the reverse effect appears. The spectral distribution of the resulting sum-frequency radiation is calculated in the first approximation of the iterative method. There is a general tendency to narrowing of the spectral distribution of the generated radiation in the course of PUC. Moreover, when there is a phase mismatch present, a spectral shift of the central maximum of generated radiation towards the blue or red region, according to the signs of the phase mismatch and the typical dispersion coefficient, appears in the later phases of the PUC.