Mode properties of circularly symmetric waveguides with one special type ofbianisotropy are studied using finite element approach. We find that thepolarization degeneracy in circularly symmetric waveguides can be eliminated,by introducing intrinsic crossing coupling between electric and magneticmoments in the constituent units of the waveguide media. Breaking thepolarization degeneracy in high order mode groups is also confirmednumerically. With the bianisotropic parameters chosen in this work, the x andy-polarized modes remain decoupled. Typically, the y-polarized modes remaincompletely unchanged, while the x-polarized modes are turned into leaky modesthat are lossy along propagation direction. A perturbation model from coupledmode theory is developed to explain the results and shows excellent agreement.Such asymmetric behavior between different polarizations might be feasible anduseful for developing compact polarizers in terahertz or mid-infrared regime.
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