We present an innovative beamline for extreme ultraviolet (XUV)-infrared (IR) pump-probe reflection spectroscopy in solids with attosecond temporal resolution. The setup uses an actively stabilized interferometer, where attosecond pulse trains or isolated attosecond pulses are produced by high-order harmonic generation in gases. After collinear recombination, the attosecond XUV pulses and the femtosecond IR pulses are focused twice in sequence by toroidal mirrors, giving two spatially separated interaction regions. In the first region, the combination of a gas target with a time-of-flight spectrometer allows for attosecond photoelectron spectroscopy experiments. In the second focal region, an XUV reflectometer is used for attosecond transient reflection spectroscopy (ATRS) experiments. Since the two measurements can be performed simultaneously, precise pump-probe delay calibration can be achieved, thus opening the possibility for a new class of attosecond experiments on solids. Successful operation of the beamline is demonstrated by the generation and characterization of isolated attosecond pulses, the measurement of the absolute reflectivity of SiO2, and by performing simultaneous photoemission/ATRS in Ge.

中文翻译：

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用于顺序双焦点几何中阿秒瞬态反射光谱的新型光束线

我们提出了一种用于固体中极紫外 (XUV)-红外 (IR) 泵浦探针反射光谱的创新光束线，具有阿秒时间分辨率。该装置使用主动稳定干涉仪，其中阿秒脉冲序列或孤立的阿秒脉冲由气体中的高次谐波产生。共线复合后，阿秒 XUV 脉冲和飞秒 IR 脉冲通过环形镜依次聚焦两次，形成两个空间分离的相互作用区域。在第一个区域，气体目标与飞行时间光谱仪的组合允许进行阿秒光电子能谱实验。在第二个焦点区域，XUV 反射计用于阿秒瞬态反射光谱 (ATRS) 实验。由于可以同时进行两次测量，可以实现精确的泵-探针延迟校准，从而为固体阿秒级新实验开辟了可能性。光束线的成功运行通过隔离阿秒脉冲的生成和表征、SiO2 的绝对反射率的测量以及在 Ge 中执行同步光电发射/ATRS 来证明。