In this paper, we present numerical methodsfor the determination of solitons, that consist in spatially localizedstationary states of nonlinear scalar equations or coupled systemsarising in nonlinear optics.We first use the well-known shooting method in order to findexcited states (characterized by the number k of nodes) for theclassical nonlinear Schrödinger equation. Asymptotics can thenbe derived in the limits of either large k are large nonlinear exponents σ.In a second part, we compute solitons for a nonlinearsystem governing the propagation of two coupled waves in a quadratic media in anyspatial dimension, starting from one-dimensional states obtained with a shooting method and considering the dimension as a continuation parameter. Finally, we investigate the case of three wavemixing, for which the shooting method is not relevant.
