Dorner-Kirchner Martin, Shumakova Valentina, Coccia Giulio, Kaksis Edgar, Schmidt Bruno E, Pervak Vladimir, Pugzlys Audrius, Baltuška Andrius, Kitzler-Zeiler Markus, Carpeggiani Paolo Antonio
Photonics Institute, Technische Universität Wien, A-1040 Vienna, Austria.
Christian Doppler Laboratory for Mid-IR Spectroscopy and Semiconductor Optics, University of Vienna, A-1090 Vienna, Austria.
ACS Photonics. 2022 Dec 29;10(1):84-91. doi: 10.1021/acsphotonics.2c01021. eCollection 2023 Jan 18.
In this work, we introduce a simplified approach to efficiently extend the high harmonic generation (HHG) cutoff in gases without the need for laser frequency conversion via parametric processes. Instead, we employ postcompression and red-shifting of a Yb:CaF laser via stimulated Raman scattering (SRS) in a nitrogen-filled stretched hollow core fiber. This driving scheme circumvents the low-efficiency window of parametric amplifiers in the 1100-1300 nm range. We demonstrate this approach being suitable for upscaling the power of a driver with an optimal wavelength for HHG in the highly desirable XUV range between 200 and 300 eV, up to the carbon K-edge. Due to the combination of power scalability of a low quantum defect ytterbium-based laser system with the high conversion efficiency of the SRS technique, we expect a significant increase in the generated photon flux in comparison with established platforms for HHG in the water window. We also compare HHG driven by the SRS scheme with the conventional self-phase modulation (SPM) scheme.
在这项工作中,我们引入了一种简化方法,无需通过参量过程进行激光频率转换,就能有效地扩展气体中的高次谐波产生(HHG)截止频率。相反,我们通过在充氮的拉伸空心光纤中利用受激拉曼散射(SRS)对Yb:CaF激光进行后压缩和红移。这种驱动方案避开了参量放大器在1100 - 1300纳米范围内的低效率窗口。我们证明了这种方法适用于扩大驱动源的功率,该驱动源具有在200至300电子伏特这一非常理想的极紫外(XUV)范围内用于HHG的最佳波长,直至碳K边。由于基于低量子缺陷镱的激光系统的功率可扩展性与SRS技术的高转换效率相结合,我们预计与水窗中已有的HHG平台相比,产生的光子通量将显著增加。我们还将由SRS方案驱动的HHG与传统的自相位调制(SPM)方案进行了比较。