Generation of Femtosecond Laser Pulse at 1053 nm with Contrast of 10^?11 by Optical-Parametric Amplification

A high contrast 1053 nm femtosecond laser pulse with free background is demonstrated based on non-collinear optical-parametric amplification (NOPA). By permuting the signal and idler in two stages of NOPAs, 48.2 fs, 62 μJ laser pulse at 1053 nm with contrast ratio of 2.3×10^?11 is obtained within the time scale of sub-5 ps. The beam quality factors M² for tangential and sagittal directions are 1.59 and 1.30, respectively. This work not only proves a feasible way to generate a clean femtosecond laser pulse but can also be employed as an ideal frontend for ultrashort ultrahigh intensity Nd:glass-based laser systems.