1. School of Opto-electronical Engineering, Xi’an Technological University 1 , Xi’an 710021, China
2. Xi’an Lumcore Optoelectronics Technologies Co., Ltd. 2 , Xi’an 710077, China
3. Department of electronic engineering, Xi’an University of Technology 3 , Xi’an 710048, China
4. Institute of Atomic and Molecular Science, Shaanxi University of Science and Technology 4 , Xi’an 712081, China