1. Terahertz Technology Innovation Research Institute, Terahertz Spectrum and Imaging Technology Cooperative Innovation Center, Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology 1 , Shanghai 200093, China
2. Shanghai Institute of Intelligent Science and Technology, Tongji University 2 , Shanghai 200092, China
3. School of Physics, University of Wollongong 3 , Wollongong, New South Wales 2522, Australia
4. Faculty of Physics, Lomonosov Moscow State University 4 , Leninskie Gory 1, Moscow 19991, Russia