Gaussian Soliton Solution in (2+1)-Dimensional Logarithmically Saturable Nonlinear Media

Through solving the nonlinear Schrödinger equation satisfied by optical field in logarithmically saturable media, a set of solutions were found. We assumed the occupation of the inner modes (i.e. self-consistent solutions) shows the Poisson distribution, and obtained the Gaussian solitons. We also found the solitons solution exists just as the nonlinear coefficient must be certain value, and the beam spot size would be restricted in a fixed value, otherwise the beam spot size takes certain oscillation on. By numerical simulation, we found the beam spot size oscillation form and amplitude rely directly on the initial beam spot size and its first-order derivative.