Numerical and theoretical study of the generation of extreme ultraviolet radiation by relativistic laser interaction with a grating
Numerical and theoretical study of the generation of extreme ultraviolet radiation by relativistic laser interaction with a grating
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DOI：
10.1063/1.3485119
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发表时间：
2010-09
影响因子：
2.2
通讯作者：
X. Lavocat-Dubuis;J. Matte
中科院分区：
文献类型：
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作者：
X. Lavocat-Dubuis;J. Matte
对飞秒相对论强度激光脉冲与亚波长周期性光栅相互作用产生的谐波进行了数值和理论研究。对于正常的入射，强烈的，在光栅周期和其谐波的波长的相干发射，获得几乎平行于目标表面，由于相对论电子束从每个突起发出。对于斜入射（30°），仅看到光栅周期性的偶次谐波，但是具有甚至更高的强度。这是由于来自光栅突起的发射的相长干涉。沿着光栅表面的发射沿着是由阿秒脉冲串组成的，因此不需要使用滤波器。24次谐波的效率大于10−4。当相似性参数S=ne/（a0 nc）（λ neλL/IL 1/2）保持固定时，转换效率相当恒定，并且当S ≥ 4时转换效率最佳。这里，ne和nc是电子密度和临界密度。
The generation of harmonics by the interaction of a femtosecond, relativistic intensity laser pulse with a grating of subwavelength periodicity was studied numerically and theoretically. For normal incidence, strong, coherent emission at the wavelength of the grating period and its harmonics is obtained, nearly parallel to the target surface, due to relativistic electron bunches emanating from each protuberance. For oblique incidence (30°), only even harmonics of the grating periodicity are seen, but with an even higher intensity. This is due to constructive interference of the emission from the grating protuberances. The emission along the grating surface is composed of trains of attosecond pulses; therefore there is no need to use a filter. An efficiency greater than 10−4 is obtained for the 24th harmonic. The conversion efficiency is fairly constant when the similarity parameter S=ne/(a0nc)(∝neλL/IL1/2) is held fixed, and is optimum when S≃4. Here, ne and nc are the electron density and the critical de...