NONLINEAR DYNAMICS OF BEAM PARAMETERS AND INTENSITY IN A UNIDIRECTIONAL RING LASER WITH A HOMOGENEOUSLY BROADENED LINE

A model of the dynamics of a single-longitudinal-mode unidirectional ring laser with a homogeneously broadened medium is proposed. The model includes the transverse variation of the field and of the material parameters and is based on a treatment of the round-trip propagation of a beam in a nonlinear medium rather than on an expansion in terms of the empty-cavity modes. In particular, the case of adiabatically eliminated polarization and inversion is studied. A three-dimensional point mapping is obtained and analyzed. It is shown that this model describes stationary regimes with mode deformation and spatiotemporal (quasi-periodic or periodic) oscillations of both the beam parameters (beam radius and phase-front curvature) and the intensity on the axis. © 1990 Optical Society of America.