[Ye, Qi-wei;Yang, Helin] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Hubei, Peoples R China.^[Nie, Yan;Gong, Rongzhou] Huazhong Univ Sci & Technol, Sch Optic & Elect Informat, Wuhan 430074, Peoples R China.^[Xiao, Boxun] Yangtze Univ, Engn Geophys Res Ctr, Wuhan 434023, Peoples R China.