1. State Key Laboratory of Precision Spectroscopy, East China Normal University 1 , Shanghai 200241, China
2. School of Physics and Electronic Science, East China Normal University 2 , Shanghai 200241, China
3. Collaborative Innovation Center of Extreme Optics, Shanxi University 3 , Taiyuan, Shanxi 030006, China
4. NYU-ECNU Joint Institute of Physics, New York University at Shanghai 4 , Shanghai 200062, China