We present a recent progress of the SG-II 5PW facility, which designed a multi-petawatt ultrashort pulse laser based on optical parametric chirped-pulse amplification (OPCPA). The prior two optical parametric amplifiers have been accomplished and chirped pulses with an energy of 49.7 J and a full-width-at-half-maximum (FWHM) spectrum bandwidth of 85 nm have been achieved. In the PW-scale optical parametric amplification (OPA), with the pump pulse that has an energy of 118 J from the second harmonic generation of the SG-II 7th beam, the pump-to-signal conversion efficiency is up to 41.9%, which to the best of our knowledge is the highest among all of the reported values for OPCPA systems. The compressed pulse is higher than 37 J in 21 fs (1.76 PW), and the focal spot is ${\sim}10~\unicode[STIX]{x03BC}\text{m}$ after the closed-loop corrections by the adaptive optics. Limited by the repetition of the pump laser, the SG-II 5PW facility operates one shot per hour. It has successfully been employed for high energy physics experiments.

中文翻译：

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SG-II 5PW激光装置分析及建设现状

我们介绍了 SG-II 5PW 设施的最新进展，该设施设计了一种基于光学参量啁啾脉冲放大 (OPCPA) 的多拍瓦超短脉冲激光器。之前的两个光参量放大器已经完成，啁啾脉冲的能量为 49.7 J，半高全宽 (FWHM) 光谱带宽为 85 nm。在 PW 尺度的光参量放大 (OPA) 中，SG-II 第 7 光束的二次谐波产生的泵浦脉冲能量为 118 J，泵浦到信号的转换效率高达 41.9%，据我们所知，这是 OPCPA 系统所有报告值中最高的。压缩脉冲在 21 fs (1.76 PW) 内高于 37 J，焦点为${\sim}10~\unicode[STIX]{x03BC}\text{m}$在自适应光学系统进行闭环校正后。受限于泵浦激光器的重复，SG-II 5PW 设备每小时运行一次。它已成功用于高能物理实验。