[1] Tianjin Univ, Sch Precis Instruments & Optoelect Engn, Tianjin 300072, Peoples R China
[2] Shanghai Jiao Tong Univ, State Key Lab Adv Opt Commun Syst & Networks, Shanghai 200240, Peoples R China
[3] Xi An Jiao Tong Univ, Sch Informat & Commun Engn, Xian 710049, Peoples R China
[4] Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R China