1. Department of Electronic Engineering; Tsinghua National Laboratory for Information Science and Technology (TNList); Tsinghua University; Beijing 100084 China
2. Department of Physics; Tsinghua University; Beijing 100084 China
3. Xi'an Zoomview Optoelectronics Science and Technology Co., LTD; Xian 710065 China
4. FLIR Systems (Shanghai) Co., LTD. Beijing Branch; Beijing 100004 China
5. Institute of Laser Engineering; Beijing University of Technology; Beijing 100124 China
6. School of Materials Science and Engineering; Tsinghua University; Beijing 100084 China