Phase modulation in second-order nonlinear-optical processes

Abstract

If three light pulses interact in a second-order nonlinear-optical process with a phase mismatch, the pulses may acquire a significant phase modulation. This phase modulation leads to a modification of the spectrum of the pulses and may offer the possibility of compressing the pulses. In this paper we discuss the effects of the ratio of intensities of the interacting pulses and the amount of phase mismatch on the phase modulation using analytical and numerical results. When the phase mismatch is small, it turns out that the modulation is also strongly influenced by the initial phase difference between the fields. Finally, we study the combined effects of a phase mismatch and a difference in group velocity on the spectrum and intensity profile of the interacting pulses.