1. College of Physics, Sichuan University, Chengdu 610064, China
2. College of Electronic Engineering, Chengdu University of Information Technology, Chengdu 610225, China
3. College of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 400047, China
4. School of Physics and Electronic Engineering, Sichuan Normal University, Chengdu 610066, China