Adiabatic and intrinsic modes for wave propagation in guiding environments with longitudinal and transverse variation: continuously refracting media

The adiabatic and intrinsic mode formalism for nonuniform propagation environments, developed and tested in a companion paper (ibid., vol.39, no.8, p.1130-36, 1991), is applied to continuously refracting media. The first example involves a guiding refractive index profile with transverse and longitudinal, but coordinate separable, variation that may be regarded as a prototype for this class of waveguides. A second example involves a nonseparable profile with a guiding-to-antiguiding transition that converts an initially well trapped mode into a radiated beam. Both examples demonstrate the problems encountered in achieving a good parametrization for tracking mode-like wave phenomena under rather general conditions