论文标题
繁殖强烈的几秒高谐波脉冲的繁殖生成
Propagation-assisted generation of intense few-femtosecond high-harmonic pulses
论文作者
论文摘要
最近，通过在单个原子中吸收至少10种极端硫酸含量（XUV）光子[Senfftleben \ textIt {et et al。}，Arxiv1911.01375]，持续的强度高谐波产生（HHG）来源的持续发展使原子高度非线性电离化。在这里，我们调查了重塑30厘米长的HHG XE培养基中基本的，几个周期的，近红外（NIR）驱动激光的作用，这在强烈的HHG脉冲中发挥了作用。使用高于相匹配的HHG所需的入射NIR强度，可以通过测量NIR Blueshift和沿HHG培养基的荧光来发现重塑的特征。这些结果通过数值计算很好地重现，这些计算显示了HHG培养基中NIR脉冲的时间压缩。模拟预测，在重新调整了320 nm的XUV束腰半径后，可以在焦平面中获得干净的Attosent脉冲序列，估计的XUV峰强度为9x10^15 w/cm^2。我们的结果表明，现在只能使用适度功能强大的台式光源来获得以前仅在大规模设施中可用的XUV强度。
The ongoing development of intense high-harmonic generation (HHG) sources has recently enabled highly nonlinear ionization of atoms by the absorption of at least 10 extreme-ultraviolet (XUV) photons within a single atom [Senfftleben \textit{et al.}, arXiv1911.01375]. Here we investigate the role that reshaping of the fundamental, few-cycle, near-infrared (NIR) driving laser within the 30-cm-long HHG Xe medium plays in the generation of the intense HHG pulses. Using an incident NIR intensity that is higher than what is required for phase-matched HHG, signatures of reshaping are found by measuring the NIR blueshift and the fluorescence from the HHG medium along the propagation axis. These results are well reproduced by numerical calculations that show temporal compression of the NIR pulses in the HHG medium. The simulations predict that after refocusing an XUV beam waist radius of 320 nm and a clean attosecond pulse train can be obtained in the focal plane, with an estimated XUV peak intensity of 9x10^15 W/cm^2. Our results show that XUV intensities that were previously only available at large-scale facilities can now be obtained using moderately powerful table-top light sources.
