SPATIAL PATTERN-FORMATION AND INSTABILITIES IN RESONATORS WITH NONLINEAR DISPERSIVE MEDIA

We discuss instabilities of the fundamental single-transverse-mode sol ution and the formation of new transverse spatial patterns in optical systems, containing nonlinearly absorbing two-level media using two tr ansverse cavity geometries (rectangular and cylindrical). Under the ap propriate approximations, these two models can be described by the sam e set of dynamical equations. Though the equations for the two models differ in their coefficients, their dynamical solutions are comparable . We find hysteresis phenomena associated with transitions in the tran sverse structure of the intensity which are completely different from the steady-state bistability and hysteresis found in theories of singl e-mode operation.