1. Beijing Key Lab for Precision Optoelectronic Measurement Instrument and Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, P. R. China
2. Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Center for Micro-Nanotechnology, Key Lab of Advanced Optoelectronic Quantum Design and Measurement, Ministry of Education, School of Physics, Beijing Institute of Technology, Beijing 100081, P. R. China
3. Kunming Institute of Physics, Kunming 650223, P. R. China