Highly efficient terahertz radiation from a thin foil irradiated by a high-contrast laser pulse
Highly efficient terahertz radiation from a thin foil irradiated by a high-contrast laser pulse
复制标题
高对比度激光脉冲照射薄箔产生高效太赫兹辐射
DOI：
10.1103/physreve.94.033206
复制
发表时间：
2016-09-21
影响因子：
2.4
通讯作者：
Kodama, R.
中科院分区：
文献类型：
--
作者：
Jin, Z.;Zhuo, H. B.;Kodama, R.
利用单次太赫兹时域光谱系统记录了超高对比度超短相对论激光脉冲辐照薄金属薄片后产生的径向偏振太赫兹辐射。当靶的厚度从30 μ m减小到2 μ m时，太赫兹辐射的持续时间从5 ps增加到20 ps以上，辐射能量急剧增加，达到10.5mJ/脉冲，相应的激光-太赫兹辐射能量转换效率为1.7%。有效的太赫兹辐射可以归因于反射（减速和加速）的激光驱动的超热电子的靶后鞘电场。实验结果与一个简单的模型以及粒子模拟相一致。
Radially polarized intense terahertz (THz) radiation behind a thin foil irradiated by ultrahigh-contrast ultrashort relativistic laser pulse is recorded by a single-shot THz time-domain spectroscopy system. As the thickness of the target is reduced from 30 to 2 mu m, the duration of the THz emission increases from 5 to over 20 ps and the radiation energy increases dramatically, reaching similar to 10.5mJ per pulse, corresponding to a laser-to-THz radiation energy conversion efficiency of 1.7%. The efficient THz emission can be attributed to reflection (deceleration and acceleration) of the laser-driven hot electrons by the target-rear sheath electric field. The experimental results are consistent with that of a simple model as well as particle-in-cell simulation.