For experiments in plasma, nuclear, and high-energy physics, there is a strong demand for laser pulses exhibiting relativistic intensity, few-cycle pulse duration, and a very high contrast. Here we present a picosecond-pumped optical parametric chirped pulse amplification (OPCPA) system delivering pulses at 10 Hz repetition rate with the following key parameters: a compressed pulse duration of less than 7 fs (close to the Fourier limit), a contrast of better than ${10}^{11}$ starting from 1 ps before the main pulse, and a peak intensity of $6.9\times {10}^{19}\mathrm{W}/{\mathrm{cm}}^2$ achieved with an off-axis parabolic mirror (f/1.6). In a proof-of-principle experiment, these pulses were used to generate high harmonics from solid surfaces with photon energies exceeding 55 eV. These results underline the promising perspectives of the reported system for relativistic light–matter interaction experiments and attosecond science.

中文翻译：

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皮秒泵浦OPCPA具有高对比度的相对论性少周期脉冲

对于等离子体，核和高能物理中的实验，强烈要求显示相对论强度，短周期脉冲持续时间和非常高的对比度的激光脉冲。在这里，我们介绍了一个皮秒级泵浦光参量pulse脉冲放大（OPCPA）系统，该系统以10 Hz重复频率提供具有以下关键参数的脉冲：压缩脉冲持续时间小于7 fs（接近傅里叶极限），对比度更好比${10}^{11}$ 从主脉冲之前的1 ps开始，峰值强度为 $6.9\times {10}^{19}\mathrm{w\; ^}/{\mathrm{厘米}}^{\mathrm{2个}}$使用离轴抛物面镜（f / 1.6）可以实现。在原理验证实验中，这些脉冲用于从光子能量超过55 eV的固体表面产生高次谐波。这些结果强调了所报道的系统的相对论光-物质相互作用实验和阿秒科学的有前途的前景。