Hybrid-Frequency Cutoffs in Gyrotropic Waveguides (Short Papers)

The behavior of the Brillouin diagram /spl omega/ versus /spl beta//sub z/ is analyzed for axially magnetized gyrotropic waveguides in the vicinity of the hybrid frequencies /spl omega//sub k/ and /spl omega//sub i/. Starting from the exact dispersion relation for the modes in the waveguides under consideration it is shown that 1) the dispersion curves terminate at discrete cutoff points located along the /spl omega/ = spl omega//sub k/, /spl omega//sub i/ line and 2) the group velocity at these points is zero. These results modify the behavior of the dispersion curves existing in the literature.