1. Department of electronic information engineering, Suzhou Institute of Technology, Jiangsu University of Science and Technology, Zhangjiagang, People’s Republic of China
2. Department of physics, Suzhou Institute of Technology, Jiangsu University of Science and Technology, Zhangjiagang, People’s Republic of China
3. School of Mathematics and Physics, Anhui University of Technology, Ma’anshan, People’s Republic of China