Analysis the cross-polarized wave generation: Influence of the quadratic and cubic spectral phase with different pump energy fluence

In this paper, we present the comprehensive study of the influence of quadratic and cubic spectral phase on cross-polarized wave (XPW) generation, including conversion efficiency, spectrum broadening, and duration shortening with different pump energy fluence, using a sub-30 fs laser pulse with 2-order supper Gaussian top-hat spectrum. This kind of broad top-hat spectrum, which would support very short fs pulse, can be obtained from acousto-optic programmable dispersive filter (AOPDF) technique. Different nonlinear processes that contribute to the generation of cross-polarized wave, including conversion efficiency and spectrum broadening, are theoretically compared. In addition, unlike the results given by previous authors, our analysis shows that the amount of XPW spectrum broadening relative to input linear chirp is asymmetric with respect to the zero chirp point, and the negative chirped pulse will result more spectral broadening compared to the pulse that has the same amount but positive chirp. We believe, our analysis presented here would result more in-depth of understanding about the XPW technique.