论文标题
在晶体硅中的高阶谐波生成的蓝光，受到强烈飞秒近红外激光脉冲的影响
Blueshift of high-order harmonic generation in crystalline silicon subjected to intense femtosecond near-infrared laser pulse
论文作者
论文摘要
我们介绍了晶体硅的高阶谐波产生，受到强烈的近红外30FS激光脉冲。谐波光谱从近红外延伸到极端的紫外光谱区域。根据脉冲激光强度，我们区分了两个谐波产生的态度：（i）扰动状态：通过多光子和隧道过渡在激光脉冲的每个半周期中出生的电子孔对在激光电场中加速并获得动能；然后，通过发射单个高能量光子，电子孔对在基态下重组。最终的高谐波频谱由奇数谐波顺序的尖峰组成。 （ii）非扰动状态：谐波的强度增加，它们的光谱宽度扩大，谐波的位置转移到较短的波长。硅中高谐波的蓝升是独立于谐波顺序的，这可能有助于连续可调的XUV源的设计。
We present the generation of high order harmonics in crystalline silicon subjected to intense near-infrared 30fs laser pulse. The harmonic spectrum extends from the near infrared to the extreme ultraviolet spectral region. Depending on the pulsed laser intensity, we distinguish two regimes of harmonic generation: (i) perturbative regime: electron-hole pairs born during each half-cycle of the laser pulse via multiphoton and tunnel transitions are accelerated in the laser electric field and gain kinetic energy; the electron-hole pairs then recombine in the ground state by emitting a single high-energy photon. The resultant high harmonic spectrum consists of sharp peaks at odd harmonic orders. (ii) non-perturbative regime: the intensity of the harmonics increases, their spectral width broadens and the position of harmonics shifts to shorter wavelengths. The blueshift of high harmonics in silicon are independent on the harmonic order which may be helpful in the design of continuously tunable XUV sources.
