Boosting laboratory photoelectron spectroscopy by megahertz high-order harmonics
Boosting laboratory photoelectron spectroscopy by megahertz high-order harmonics
复制标题
DOI：
10.1088/1367-2630/17/1/013035
复制
发表时间：
2015-01-20
影响因子：
3.3
通讯作者：
Widdra, Wolf
中科院分区：
文献类型：
--
作者：
Chiang, Cheng-Tien;Huth, Michael;Widdra, Wolf
自从光电效应被发现以来，光电子能谱已经发展成为研究材料电子结构的最强大的技术。此外，最近使用高次谐波产生(HHG)的阿秒光源与光电子实验相结合，可以实时直接观察电子动力学。然而，这些实验的效率在很大程度上受到空间电荷效应的限制，光激发的重复频率通常很低。在这里，我们展示了在光电子计数速率为1×10(5)个电子/S的情况下基于HHG的实验室光电子能谱实验，并在几秒钟内表征了Ag(001)的电子能带结构的主要特征，而没有明显的空间电荷效应退化。将兆赫重复频率的紧凑型HHG光源与使用飞行时间光谱学的高效光电子收集相结合，可以在灵活的实验室环境中快速研究电子能带，并为阿秒光谱和显微镜的有效设计铺平道路。
Since the discovery of the photoelectric effect, photoelectron spectroscopy has evolved into the most powerful technique for studying the electronic structure of materials. Moreover, the recent combination of photoelectron experiments with attosecond light sources using high-order harmonic generation (HHG) allows direct observation of electron dynamics in real time. However, the efficiency of these experiments is greatly limited by space-charge effects at typically low repetition rates of photoexcitation. Here, we demonstrate HHG-based laboratory photoemission experiments at a photoelectron count rate of 1 x 10(5) electrons/s and characterize the main features of the electronic band structure of Ag(001) within several seconds without significant degradation by the space-charge effects. The combination of a compact HHG light source at megahertz repetition rates with the efficient collection of photoelectrons using time-of-flight spectroscopy may allow rapid investigation of electronic bands in a flexible laboratory environment and pave the way for an efficient design of attosecond spectroscopy and microscopy.