Key Laboratory for Physical Electronics and Devices of Ministry of Education;
Xi'an Jiaotong University;
Xi'an 710049;
Department of Physics;
University of Arkansas;
Fayetteville;
Arkansas 72701;
USA;
State Key Laboratory of Transient Optics and-Technology;
Xi'an Institute of Optics and Precision Mechanics;
Chinese Academy of Sciences;
Xi'an 710068;
