Experiments on the generation of high optical harmonics demonstrating that relativistic regimes of interaction of radiation with matter can be implemented in the field of mid-infrared laser pulses with a peak power of 0.3 TW have been reported. The observation of relativistic phenomena at such extraordinary low peak powers of the laser field becomes possible because of the formation of a high-quality space-time mode of the laser field with an exactly specified polarization state. Such a field structure ensures a high intensity of radiation in the focus of the beam and the effective acceleration of electrons by a low-frequency electromagnetic field of a high-contrast laser pulse with an exactly specified polarization at the extremely sharp vacuum-solid interface.

中文翻译：

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兆瓦以下激光脉冲场中的相对论非线性光学现象

已经报道了产生高光谐波的实验，该实验表明可以在峰值功率为0.3 TW的中红外激光脉冲领域中实现辐射与物质相互作用的相对论形式。由于形成了具有精确指定的偏振态的高质量的激光场时空模式，因此可以在如此低的激光场峰值功率下观察相对论现象。这种场结构确保了在非常尖锐的真空-固体界面处具有精确指定极化的高对比度激光脉冲的低频电磁场的作用，从而确保了光束焦点处的高辐射强度以及电子的有效加速。