1. School of Physical Science and Technology, Chongqing key Laboratory of Micro & Nano Structure Optoelectronics, Southwest University, Chongqing 400715, People’s Republic of China
2. Henan Key Laboratory of Infrared Materials & Spectrum Measures and Applications, School of Physics, Henan Normal University, Xinxiang 453007, People’s Republic of China
3. College of Physics & Electrical Engineering, Chongqing Normal University, Chongqing 401331, People’s Republic of China