Characterization of spectral broadening and contrast enhancement in cross-polarized wave generation based on gadolinium gallium garnet crystal

Abstract

To provide seed pulses with ultra-broad bandwidth and high temporal contrast for high power laser systems, cross-polarized wave (XPW) generation based on gadolinium gallium garnet (GGG) crystal was proposed after a high-gain preamplifier. By numerical simulation, specifications of conversion efficiency with ∼23.3%, contrast enhancement by ∼9.7 orders of magnitude and spectrum of 626–1167 nm (full width at half maximum ∼ 259 nm) supporting Fourier-transfer-limit duration of 5.5fs was realized. XPW injected by fundamental wave of higher-order super-Gaussian temporal profiles presents superior characterizations. By contrast with BaF2, XPW with GGG performs a comparable contrast enhancement, higher efficiency and more remarkable spectrum broadening, indicating a prominent application in frontend.

Characterization of ultrashort double pulses and their application in attosecond physics

“…From this relation, one can see that in time domain the generated XPW pulse is shorter than the generating pulse, so apart from modifying the polarization state, this process has a slight spectral broadening effect too. Moreover, the generated XPW has a smoother spectrum and a flatter spectral phase compared to the spectrum and spectral phase of the incident pulse, because of the temporal filtering effect of the frequencyconserved third-order nonlinear process [114]- [116].…”