ANGLE-DEPENDENT NONLINEAR MODES OF A CYLINDRICAL WAVE-GUIDE

Solutions of the wave equation for a cylindrical waveguide with cladding in which the dielectric constant depends nonlinearly on the optical field are obtained by numerical methods. We consider both saturable and nonsaturable nonlinearities. Asymmetrical solutions for which the field distributions have no axial symmetry are found. It is shown that the energy of such modes is less than the energy of the axially symmetric modes. The asymmetric modes exist in an interval of wave vectors n above a minimum value n at which the branching of the asymmetric mode away from the symmetric one first occurs. The dependences of the total energy and the value n on the core diameter are obtained by expanding the field in powers of (n - no). Solutions that are periodic in angle with several maxima and minima along the interface of the core and the cladding are also considered. © 1990 Optical Society of America.