1. State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy
of Sciences, 500 Yutian Road, Shanghai 200083, China
2. University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China
3. Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 2601, Australia
4. School of Information Engineering, Zhengzhou University, Zhengzhou 450052, China