Nonlinear Schrödinger equation and semiclassical description of the light–atom interaction

In this paper, we consider the nonlinear Schrödinger equation describing the light–atom interaction while taking into account damping due to spontaneous emission. We demonstrate that the optical Bloch equations with damping due to spontaneous emission can be derived immediately from the nonlinear Schrödinger equation without any phenomenology and quantization of radiation. The steady-state solutions of the nonlinear optical Bloch equations are obtained and compared with those obtained for linear optical equations. In this approximation, the light scattering by an atom is considered.