[He-Xiu Xu; Yanzhao Wang; Chaohui Wang] Department of Electronic Science and Technology, Air force Engineering University, Xi'an, 710051 China
[Shiwei Tang] Department of Physics, Faculty of Science, Ningbo University, Ningbo, 315211 China
[Xiaohui Ling] College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang, 421002 China
[Jiafeng Zhou] Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ UK
[Guangwei Hu; Menghua Jiang] Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583 Singapore
