Design and experimental demonstration of a high conversion efficiency OPCPA pre-amplifier for petawatt laser facility
Design and experimental demonstration of a high conversion efficiency OPCPA pre-amplifier for petawatt laser facility
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DOI：
10.1017/hpl.2018.52
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发表时间：
2018-12
影响因子：
4.8
通讯作者：
X. Liang;Xinglong Xie;Jun Kang;Qingwei Yang;Hui Wei;Meizhi Sun;Jianqiang Zhu
中科院分区：
文献类型：
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作者：
X. Liang;Xinglong Xie;Jun Kang;Qingwei Yang;Hui Wei;Meizhi Sun;Jianqiang Zhu
介绍了一种宽带光参量啁啾脉冲放大器（OPCPA）的设计和实验，该放大器在808 nm波长处具有高转换效率和良好的光束质量。使用三维空间和时间的数值模型，几个必要的设计考虑，以实现高转换效率，良好的光束质量和良好的输出稳定性进行了讨论。为了提高光参量放大器的转换效率，同时拓宽放大信号带宽，采用耗散双晶体结构光参量放大器（OPA）中放大闲频的概念，对非线性晶体长度和OPCPA参数进行了分析和优化。在实验中，放大器的两个OPCPA级的“L”型配置，使用优化的参数进行了演示。实现了160 mJ的放大信号能量，总泵浦信号效率为35%（OPCPA第2级的效率为43%）。信号脉冲输出带宽达到80 nm，信号脉冲压缩至24 fs。在泵浦能量变化3%时，能量稳定性达到1.67%RMS。优化后的OPCPA放大器工作在1 Hz的重复频率，并被用作SG-II 5 PW激光装置主放大器的前端注入。
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.