1. Institute of Laser and Opto-Electronics, College of Precision Instruments and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China
2. Key Laboratory of Opto-Electronics Information Technology, Ministry of Education, Tianjin University, Tianjin 300072, China
3. College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266590, China
4. Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin 300072, China
5. Center of Material Science, National University of Defense Technology, Changsha 410073, China