Pulse shaping and processing by cascaded third-harmonic generation in quasiperiodic optical superlattices

Theoretical investigation on the temporal and spectral distributions of cascade third harmonic generation in a quasiperiodically optical superlattice is presented. Pulse shaping and integrated energy conversion are studied, for both input transform-limited and chirped pulses, as well as for both phase matched and phase mismatched configurations. Not only the phase mismatch between the center frequencies of the fundamental and harmonic pulses but also the group velocity mismatches (GVM) among the interacting pulses are considered. The pulse shaping features consisting of a multiplicity in phase and amplitude are observed. Additionally, there are some interesting phenomena in harmonic energy conversion, which provide more flexibility for harmonic generations in the ultrashort pulse range.