1. The Key Laboratory of Opto-Electronics Information and Technology, Institute of Laser and Opto-Electronics, College of Precision Instruments and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China
2. School of Opto-Electronic Engineering, Zaozhuang University, Zaozhuang 277160, China
3. School of Electric Power, North China University of Water Resources and Electric Power, Zhengzhou 450045, China
4. Advantest (China) Co., Ltd, Shanghai 201203, China
5. College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China