1. Laboratoire de Physique des Lasers (CNRS-UMR 7538), Université Paris 13, 99 Av. J.B. Clément, 93430 Villetaneuse, France
2. Atomic and Molecular Physics Group, Institute of Physics, Belgrade, Pregrevica, 11080 Zemun, Serbia
3. Physics Department, Umm Al Qura University, P.O. Box 715, Mecca, Saudi Arabia