Aperiodically Poled Nonlinear Crystals as Sources of Multi-Frequency Laser Radiation

The new multi-frequency process, which consists of three coupled nonlinear optical interactions: two parametric down-conversions and one up-conversion, in aperiodically poled nonlinear crystal is investigated. The spatial dynamics of wave intensities is studied in detail. The possibility of secondary simplification of coupled equations for correct describing the dynamics of wave interactions is demonstrated. The optimal conditions for parametrical instability of the initial stage of wave interactions are found.