Time-Resolved Angle-resolved Photoemission Spectroscopy Using High-Order Harmonic EUV Pulses

Hao Hsiang Jia^1,2*, Ying-Hao Chien¹, Hung-Wei Sun¹, Chih-Wei Luo³, Cheng-Maw Cheng², Ming-Chang Chen¹, Ping-Hui Lin²

¹Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan
²National Synchrotron Radiation Research Center, Hsinchu, Taiwan
³Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan

* Presenter:Hao Hsiang Jia, email:brian19940301@gmail.com

Angle- resolved photoelectron spectroscopy (ARPES) is one of the most direct methods of studying the electronic structure of solids. Current research are interested in dynamics of novel material, such that electron-phonon or electron-electron interactions. High-order harmonic generation (HHG) provides coherent EUV light source which can be used to probe the electronic structure at subpicosecond or even femtosecond time sale. We will present the TR-ARPES apparatus we have developed. The turnkey laser system has center wavelength of 1030 nm (1.2 eV) and pulse duration of 200 fs. Most of the power (90%) is separated to generate EUV through HHG, the remaining part delivers a pump beam with photon energy of 1.2 eV or its second harmonic (2.4 eV). We have demonstrated this table-top HHG light source is stable and has been tested for operating more than one week continuously without any realignment and maintenance. We have some preliminary results and shows that the temporal resolution of the TR-ARPES beamline is about 220 fs.

Keywords: ARPES, Time-Resolved, High-order harmonic generation