1. School of Physics & Information Technology Shaanxi Normal University Xi'an 710119 China
2. School of Optical and Electronic Information National Engineering Laboratory for Next Generation Internet Access System Huazhong University of Science and Technology No.1037 Luoyu Road Wuhan 430074 China
3. Shaanxi University of Science & Technology Department of Physics Xi'an 710021 China
4. CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology Beijing 100190 China
5. State Key Laboratory of Transient Optics and Photonics Xi'an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi'an 710119 China