Front-end system of PW laser

摘要

The fast ignitor study requires the intense chirped pulse amplification (CPA) on large-scale Nd:glass laser systems at a 1.053-μm wavelength. This system enables us to achieve 1 PW within several hundreds fs pulse duration, and intensity larger than 10{sup}20 W/cm{sup}2 at the focal spot. We developed Petawatt Module laser system (abbreviated as PWM) in 1997 [1], which has been upgraded to the Pettawatt laser (PW laser) since 2000. The front-end-system uses a broadband high-gain OPCPA to generate appropriate chirped pulses. The OPCPA [2-4] has apparent advantages over the current schemes for high energy ultrafast pulse amplification. The advantages of OPCPA technique are (1) high gain in a single-pass amplification, (2) high beam quality due to a low heat deposition, (3) small Bintegral, (4) high contrast ratio, and (5) especially the extremely broad gain bandwidth. The OPCPA system using large-size KDP crystal is possible to obtain muti-PW level. We present the experimental study of the high gain OPCPA system. The OPCPA is much more compact and its gain is higher than the currently used regenerative amplifier or multi-pass amplifier at 1-μm wavelength ensuring the stable operation.