[1] Beijing Univ Posts & Telecommun, State Key Lab Informat Photon & Opt Commun, POB 122, Beijing 100876, Peoples R China
[2] Beijing Univ Posts & Telecommun, Sch Sci, POB 122, Beijing 100876, Peoples R China
[3] Badji Mokhtar Univ, Radiat Phys Lab, Dept Phys, Fac Sci, POB 12, Annaba 23000, Algeria
[4] Wuhan Donghu Univ, Sch Elect & Informat Engn, Wuhan 430212, Hubei, Peoples R China
[5] Alabama A&M Univ, Dept Phys Chem & Math, Normal, AL 35762 USA
[6] King Abdulaziz Univ, Dept Math, Jeddah 21589, Saudi Arabia
[7] Tshwane Univ Technol, Dept Math & Stat, ZA-0008 Pretoria, South Africa