Orbital stability of standing waves for a system of nonlinear Schrödinger equations with three wave interaction

We study the existence and stability of standing waves solutions of a three-coupled nonlinear Schrödinger system related to the Raman amplification in a plasma. By means of the concentration-compactness method, we provide a characterization of the standing waves solutions as minimizers of an energy functional subject to three independent L2 mass constraints. As a consequence, we establish existence and orbital stability of solitary waves.