Specific Gaussian beams propagating inside logarithmically saturable nonlinear media

Insertion of the expression for a Gaussian beam into Maxwell's equations le ads to four coupled equations governing the evolution of beam parameters in a logarithmically saturable nonlinear medium (LSNM). Analytical solutions to the coupled equations have been deduced for cases where the incident bea m parameters slightly deviate from those of the spatial soliton. As a resul t, a detailed description to the Gaussian-type breath mode can be made. For general cases, a graphical analysis has been used to draw the main charact eristics of the Gaussian-type breath mode propagating along the LSNM.