1. Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electrical Engineering, East China Normal University, Shanghai, P. R. China
2. Shanghai Transcom Scientific Co., Ltd., 528 Ruiqing Road, 20A, Z. J. East Area Hi-Tech Medical Park, Shanghai, P. R. China
3. Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, P. R. China