Influence of the wavefront mismatch, spatial chirp and multimode pump on the beam quality of OPCPA

The beam quality and wavefront distribution of the optical parametric chirped-pulse amplification (OPCPA) front-end system of the petawatt laser has become a focus for research. The influence of wavefront mismatch, spatial chirp and multimode pump on the beam quality of OPCPA is numerically simulated and analyzed. It is shown that the beam quality and wavefront distribution becomes worse as the mismatch angle or the order of the spatial chirp increases. Meanwhile, it is also found that the beam quality and conversion efficiency of the amplified signal becomes worse as the transverse distribution of the pump laser descends