1. Univ. Polytech. Hauts-de-France, CNRS, Univ. Lille, ISEN, Centrale Lille, UMR 8520 - IEMN, DOAE, F-59313 Valenciennes, France
2. Laboratory of Physics and Modeling, EDST, Lebanese University, Tripoli 1300, Lebanon
3. Department of Physics, American University of Beirut, Bliss Street, Riad El-Solh, 1107-2020 Beirut, Lebanon