Investigation on the influences of linear chirp with different input pulse intensities on BaF2 cross-polarized wave generation

Abstract

Cross-polarized wave (XPW) generation based on BaF2 crystal is one of the most important tools in improving the contrast of ultra-intense femtosecond laser pulses at present. In this paper, the influences of linear chirp with different input pulse intensities on BaF2 XPW generation, including conversion efficiency, spectrum broadening, and pulse duration reduction are in detail simulated and discussed. Especially, the influence of linear chirp on spectrum broadening is comparatively investigated under unsaturated and intense input pulses. While the amount of spectrum broadening relative to linear chirp is symmetrical with respect to the zero chirp point under unsaturated input pulse, the results show that it is no longer those in the case under intense input pulse, and the intrinsic reason is explained in detail in this paper.