Exact spatial similaritons for the generalized (2+1)-dimensional nonlinear Schrödinger equation with distributed coefficients

Based on a similarity transformation, we obtain exact spatial bright and dark similariton pairs and bright similaritons on continuous-wave backgrounds of the generalized (2+1)-dimensional nonlinear Schrödinger equation with space-dependent diffraction, nonlinearity, and gain coefficients. Some characteristic examples with physical relevance and the interaction behaviors of these similaritons are studied.