Ishida Y, Togashi T, Yamamoto K, Tanaka M, Kiss T, Otsu T, Kobayashi Y, Shin S
ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan.
RIKEN SPring-8 Center, Sayo, Sayo, Hyogo 679-5148, Japan.
Rev Sci Instrum. 2014 Dec;85(12):123904. doi: 10.1063/1.4903788.
The paper describes a time- and angle-resolved photoemission apparatus consisting of a hemispherical analyzer and a pulsed laser source. We demonstrate 1.48-eV pump and 5.92-eV probe measurements at the ⩾10.5-meV and ⩾240-fs resolutions by use of fairly monochromatic 170-fs pulses delivered from a regeneratively amplified Ti:sapphire laser system operating typically at 250 kHz. The apparatus is capable to resolve the optically filled superconducting peak in the unoccupied states of a cuprate superconductor, Bi2Sr2CaCu2O(8 + δ). A dataset recorded on Bi(111) surface is also presented. Technical descriptions include the followings: A simple procedure to fine-tune the spatio-temporal overlap of the pump-and-probe beams and their diameters; achieving a long-term stability of the system that enables a normalization-free dataset acquisition; changing the repetition rate by utilizing acoustic optical modulator and frequency-division circuit.
本文描述了一种由半球形分析仪和脉冲激光源组成的时间和角度分辨光电子能谱仪。我们利用从典型工作频率为250kHz的再生放大钛宝石激光系统发出的相当单色的170飞秒脉冲，展示了在⩾10.5毫电子伏特和⩾240飞秒分辨率下的1.48电子伏特泵浦和5.92电子伏特探测测量。该仪器能够分辨铜酸盐超导体Bi2Sr2CaCu2O(8 + δ)未占据态中的光学填充超导峰。还给出了在Bi(111)表面记录的数据集。技术描述包括以下内容：一种微调泵浦和探测光束的时空重叠及其直径的简单程序；实现系统的长期稳定性，从而能够采集无需归一化的数据集；利用声光调制器和分频电路改变重复频率。
