“…This equation known as the nonlinear Schrödinger equation (NLS), which, depending on the physical situation takes several different forms, in a general quantum system is written as i ∂ (r, t) ∂t =Ĥ (r, t), (1.1) where i = √ −1, is the wave function, is the reduced Plank's constant, andĤ is the Hamiltonian operator. Applications of the NLS equation were found in semiconductor electronics [2,3], optics in nonlinear media [4], photonics [5], plasmas [6], fundamentation of quantum mechanics [7], dynamics of accelerators [8], mean-field theory of Bose-Einstein condensates [9], or in biomolecule dynamics [10]. In some of these fields and in many others, the NLS equation appears as an asymptotic limit for a slowly varying dispersive wave envelope propagating in a nonlinear medium [11].…”