A gyro-medium filled beam waveguide

Quasi-confocal modes for a gyro-medium filled beam waveguide are derived. The axis of beam propagation is taken coincident with the gyro-axis of the medium. The modes are found to be circularly polarized with dispersion characteristics similar to circularly polarized plane waves propagating along the gyro-axis of the medium. The addition of such a medium can thus introduce propagation cutoffs and resonances previously not present in the beam waveguide. The characteristic beam diameter and the phase correction necessary to maintain a mode are found to depend on the circular polarization of the mode. The example of a lossless gyro-plasma medium is discussed.