High Power Laser Science and Engineering, 2018, 6 (4): 04000e58, Published Online: Dec. 27, 2018
Design and experimental demonstration of a high conversion efficiency OPCPA pre-amplifier for petawatt laser facility Download: 610次
Abstract
We present the design and experiment of a broadband optical parametric chirped-pulse amplifier (OPCPA) which provides high conversion efficiency and good beam quality at 808 nm wavelength. Using a three-dimensional spatial and temporal numerical model, several design considerations necessary to achieve high conversion efficiency, good beam quality and good output stability are discussed. To improve the conversion efficiency and broaden the amplified signal bandwidth simultaneously, the nonlinear crystal length and OPCPA parameters are analyzed and optimized with the concept of dissipating amplified idler between optical parametric amplification (OPA) of two crystals configuration. In the experiment, an amplifier consisting of two OPCPA stages of ‘L’ type configuration was demonstrated by using the optimized parameters. An amplified signal energy of 160 mJ was achieved with a total pump-to-signal efficiency of 35% (43% efficiency for the OPCPA stage 2). The output bandwidth of signal pulse reached 80 nm and the signal pulse was compressed to 24 fs. The energy stability reached 1.67% RMS at 3% pump energy variation. The optimized OPCPA amplifier operates at a repetition rate of 1 Hz and is used as a front-end injection for the main amplifier of SG-II 5PW laser facility.
Xiao Liang, Xinglong Xie, Jun Kang, Qingwei Yang, Hui Wei, Meizhi Sun, Jianqiang Zhu. Design and experimental demonstration of a high conversion efficiency OPCPA pre-amplifier for petawatt laser facility[J]. High Power Laser Science and Engineering, 2018, 6(4): 04000e58.