[1] Nankai Univ, Sch Phys, Tianjin 300071, Peoples R China
[2] Nankai Univ, MOE Key Lab Weak Light Nonlinear Photon, Tianjin 300071, Peoples R China
[3] Nanjing Univ, Natl Lab Solid State Microstruct, Nanjing 210093, Jiangsu, Peoples R China
[4] Nanjing Univ, Collaborat Innovat Ctr Adv Microstruct, Nanjing 210093, Jiangsu, Peoples R China