论文标题
高谐波一代在强烈的偏僻政权中
High-harmonic generation in a strongly overdriven regime
论文作者
论文摘要
高谐波生成（HHG）通常需要仔细调整驾驶激光强度（通常为$ 10^{14} -10^{15} $ w/cm $ $^2 $）和气中参数以启用良好的相位匹配条件。与传统智慧相反，我们提出了实验结果，表明所有稀有气体中相匹配的HHG，使用高密度介质和驱动器激光强度约为$ 10^{16} $ w/cm $^2 $。实验结果通过理论模拟证实，这表明电离诱导的自相度调制和等离子体散焦，从而使自我调节的驱动激光强度达到适合良好相位匹配的水平。观察到了NIR光谱的十倍扩展，尽管使用了50-fs长的驾驶脉冲，但仍会从18-140美元的EV产生连续光谱。提出的方案代表了用于生成XUV和软X射线连续图的简单且通用的概念，非常适合瞬时吸收和反射光谱。
High-harmonic generation (HHG) normally requires a careful adjustment of the driving laser intensity (typically $10^{14} - 10^{15}$ W/cm$^2$) and gas medium parameters to enable good phase matching conditions. In contrast with conventional wisdom, we present experimental results indicating phase-matched HHG in all rare gases, using a high-density medium and a driver laser intensity of around $10^{16}$ W/cm$^2$. The experimental results are corroborated by theoretical simulations, which indicate that ionization-induced self-phase modulation and plasma defocusing self-regulate the driver laser intensity to a level that is appropriate for good phase matching. A ten-fold broadening of the NIR spectrum is observed, which results in the generation of continuous spectra from $18-140$ eV in spite of using 50-fs-long driving pulses. The presented scheme represents a simple and versatile concept for the generation of XUV and soft X-ray continua, which are ideally suited for transient absorption and reflection spectroscopy.
