Multipole vector solitons in coupled nonlinear Schrödinger equation with saturable nonlinearity

Abstract

We construct the coupled self-defocusing saturated nonlinear Schrödinger equation and obtain the dipole-dipole, tripole-dipole and dipole-tripole vector soliton solutions by changing the potential function parameters and using the square operator method of power conservation. With the increase of soliton power, the dipole-dipole, tripole-dipole and dipole-tripole vector solitons can all exist. The existence of the three kinds of vector solitons is obviously modulated by the potential function. The existence domain of three kinds of vector solitons, modulated by the potential function, is given in this work. The stability domains of three vector solitons are modulated by the soliton power of each component. The stability regions of three kinds of vector solitons expand with the increase of the power of two-component soliton. With the increase of saturation nonlinear strength, the power values of the tripole-dipole and dipole-tripole vector solitons at the critical points from stable state to unstable state decrease gradually, and yet the power of the soliton at the critical point from the stable state to the unstable state does not change.