论文标题
紧凑的强烈极限粉丝源
Compact intense extreme-ultraviolet source
论文作者
论文摘要
如今，覆盖紫外线到Terahertz光谱区域的高强度激光脉冲通常是在大量实验室中常规产生的。相反，仅使用少量来源（包括自由电子激光设施[1-3]和长高谐波（HHG）束线线[4-9]，才证明了强烈的极端粉状物（XUV）脉冲。在这里，我们演示了一个基于HHG的紧凑型XUV源的概念，该概念的重点为$ 2 \ times 10^{14} $ w/cm $ $^2 $，可能会增加$ 10^{17} $ w/cm $ $^2 $。我们的方法使用近红外（NIR）驾驶激光的紧密聚焦，并通过产生远离NIR焦点的谐波长度来最大程度地减少XUV虚拟源大小。因此，可以将XUV脉冲重新聚焦于600 nm的小光束半径，从而在适合适度（2 m）激光桌上的设置中，可以通过一个AR AROM吸收多达四个XUV光子。我们的概念代表了许多实验室中强烈的XUV脉冲的一种直接方法，为XUV强场和非线性光学实验提供了新的机会，用于XUV-PUMP XUV XUV-PUMP-PROBE光谱以及纳米级结构的相干衍射成像。
High-intensity laser pulses covering the ultraviolet to terahertz spectral regions are nowadays routinely generated in a large number of laboratories. In contrast, intense extreme-ultraviolet (XUV) pulses have only been demonstrated using a small number of sources including free-electron laser facilities [1-3] and long high-harmonic generation (HHG) beamlines [4-9]. Here we demonstrate a concept for a compact intense XUV source based on HHG that is focused to an intensity of $2 \times 10^{14}$ W/cm$^2$, with a potential increase up to $10^{17}$ W/cm$^2$ in the future. Our approach uses tight focusing of the near-infrared (NIR) driving laser and minimizes the XUV virtual source size by generating harmonics several Rayleigh lengths away from the NIR focus. Accordingly, the XUV pulses can be refocused to a small beam waist radius of 600 nm, enabling the absorption of up to four XUV photons by a single Ar atom in a setup that fits on a modest (2 m) laser table. Our concept represents a straightforward approach for the generation of intense XUV pulses in many laboratories, providing novel opportunities for XUV strong-field and nonlinear optics experiments, for XUV-pump XUV-probe spectroscopy and for the coherent diffractive imaging of nanoscale structures.
