Further advances in the field of ultrafast magnetization dynamics require experimental tools to measure the spin and electron dynamics with element-specificity and femtosecond temporal resolution. We present a new laboratory setup for two complementary experiments with light in the extreme ultraviolet (XUV) spectral range. One experiment is designed for polarization-dependent transient spectroscopy, particularly for simultaneous measurements of magnetic circular dichroism (MCD) at the 3p resonances of the 3d transition metals Fe, Co, and Ni. The second instrument is designed for resonant small-angle scattering experiments with monochromatic light allowing us to monitor spin dynamics with spatial information on the nanometer scale. We combine a high harmonic generation (HHG) source with a phase shifter to obtain XUV pulses with variable polarization and a flux of about (3 ± 1) × 1010 photons/s/harmonic at 60 eV at the source. A dedicated reference spectrometer effectively reduces the intensity fluctuations of the HHG spectrum to below 0.12% rms. We demonstrate the capabilities of the setup by capturing the energy- and polarization-dependent absorption of a thin Co film as well as the time-resolved small-angle scattering in a magnetic-domain network of a Co/Pt multilayer. The new laboratory setup allows systematic studies of optically induced spin and electron dynamics with element-specificity, particularly with MCD as the contrast mechanism with femtosecond temporal resolution and an unprecedented signal-to-noise ratio.

中文翻译：

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在极紫外光谱范围内用于超快螺旋度相关和元素特异性吸收光谱和散射的桌面设置

超快磁化动力学领域的进一步进展需要实验工具来测量具有元素特异性和飞秒时间分辨率的自旋和电子动力学。我们提出了一个新的实验室设置，用于在极紫外 (XUV) 光谱范围内进行两个互补实验。一项实验是为偏振相关瞬态光谱设计的，特别是在 3d 过渡金属 Fe、Co 和 Ni 的 3p 共振下同时测量磁圆二色性 (MCD)。第二个仪器设计用于使用单色光进行共振小角度散射实验，使我们能够使用纳米尺度的空间信息监测自旋动力学。我们将高次谐波产生 (HHG) 源与移相器相结合，以获得具有可变偏振和约 (3 ± 1) × 1010 光子/秒/谐波通量的 XUV 脉冲，在源处 60 eV。专用参考光谱仪有效地将 HHG 光谱的强度波动降低到 0.12% rms 以下。我们通过捕获 Co/Pt 多层磁畴网络中 Co 薄膜的能量和偏振相关吸收以及时间分辨小角度散射来证明该装置的能力。新的实验室设置允许系统研究具有元素特异性的光学诱导自旋和电子动力学，特别是使用 MCD 作为具有飞秒时间分辨率和前所未有的信噪比的对比机制。