1. State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
2. College of Physics and Electronic Information, Luoyang Normal University, Luoyang, China
3. Department of Physics, Zhejiang University, Hangzhou 310027, China
4. Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China