Amplification of nonlinear waves in a symmetric planar waveguide.

Abstract

The gain process of modes of a nonlinear symmetric planar waveguide is investigated. It is shown using numerical simulations that the gain process is adiabatic at low values of gain factor and that the wave envelope changes slowly, remaining close to the shape of the stable nonlinear mode. The representative point of the wave on the plane (energy integral, propagation constant) moves continuously along the stable branches of dispersion curves. When the representative point achieves the region of instability, the spatial solitons are split off from the guided mode. This process is repeated periodically due to the gain. We considered a number of typical cases of guided-wave propagation with symmetric as well as asymmetric initial conditions.