1. College of Physics and Electronic Engineering, Hainan Normal University, Haikou 571158, China
2. Key Laboratory of Laser Technology and Optoelectronic Functional Materials of Hainan Province, Hainan Normal University, Haikou 571158, China
3. Hainan International Joint Research Center for Semiconductor Lasers, Hainan Normal University, Haikou 571158, China