Spatial soliton laser

We show that the transverse field in a laser with intra-cavity Kerr lens may be approximated by a spatial soliton, and so the laser can be thought of as a "spatial soliton laser". Using a simple perturbation approach based on the nonlinear Schrodinger equation (NLS) we find analytical solutions which are in good agreement with numerical results from our master equation. This agreement is improved when we combine the soliton solution with a Gaussian dependent on the position of the Kerr lens. We discuss the limitations to the soliton perturbation theory. With appropriate placement, either a positive or a negative Kerr lens can induce spatial soliton laser action. (C) 1998 Elsevier Science B.V.