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

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 similar to 23.3%, contrast enhancement by similar to 9.7 orders of magnitude and spectrum of 626-1167 nm (full width at half maximum similar to 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. (C) 2020 The Japan Society of Applied Physics.