1. School of OPTO-Electronic Engineering, Changchun University of Science and Technology, Changchun 130022, People's Republic of China
2. State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
3. School of Physics and Electronic Engineering, Hainan Normal University, Haikou 571100, P. R. China