Helk Tobias, Berger Emma, Jamnuch Sasawat, Hoffmann Lars, Kabacinski Adeline, Gautier Julien, Tissandier Fabien, Goddet Jean-Philipe, Chang Hung-Tzu, Oh Juwon, Pemmaraju C Das, Pascal Tod A, Sebban Stephane, Spielmann Christian, Zuerch Michael
Institute of Optics and Quantum Electronics, Abbe Center of Photonics, Friedrich-Schiller University, 07743 Jena, Germany.
Helmholtz Institute Jena, 07743 Jena, Germany.
Sci Adv. 2021 May 19;7(21). doi: 10.1126/sciadv.abe2265. Print 2021 May.
The lack of available table-top extreme ultraviolet (XUV) sources with high enough fluxes and coherence properties has limited the availability of nonlinear XUV and x-ray spectroscopies to free-electron lasers (FELs). Here, we demonstrate second harmonic generation (SHG) on a table-top XUV source by observing SHG near the Ti M edge with a high-harmonic seeded soft x-ray laser. Furthermore, this experiment represents the first SHG experiment in the XUV. First-principles electronic structure calculations suggest the surface specificity and separate the observed signal into its resonant and nonresonant contributions. The realization of XUV-SHG on a table-top source opens up more accessible opportunities for the study of element-specific dynamics in multicomponent systems where surface, interfacial, and bulk-phase asymmetries play a driving role.
缺乏通量和相干特性足够高的台式极紫外（XUV）光源，限制了非线性XUV和X射线光谱学在自由电子激光（FEL）之外的应用。在此，我们通过用高谐波种子软X射线激光在钛M边附近观测二次谐波产生（SHG），证明了在台式XUV源上的二次谐波产生。此外，该实验代表了XUV中的首次SHG实验。第一性原理电子结构计算表明了表面特异性，并将观测到的信号分离为其共振和非共振贡献。在台式光源上实现XUV-SHG，为研究多组分系统中元素特异性动力学开辟了更多可及的机会，在这些系统中，表面、界面和体相不对称起着驱动作用。
