Characteristics of surface plasmonic modes in cylindrical chiral-graphene-dielectric waveguide structure

A cylindrical chiral-graphene-dielectric waveguide structure is proposed. Correspondingly, characteristics of surface plasmonic mode are theoretically investigated, including dispersion relation, intensity, phase and polarization distribution. The proposed waveguide can only support the vortex modes with the hybrid polarization distribution, which originates from the spin-momentum locking of evanescent electromagnetic waves. The circular birefringence of chiral materials releases the degeneracy between same-order vortex modes. In addition, the number of modes can be controlled by changing the radius of the dielectric nanowire and the Fermi level of graphene. The effective index and corresponding propagation length of the mode are sensitive to the chiral parameter. We believe the proposed waveguide can find some potential applications in multiplex communication, chiral sensing and the fabrication of tunable nano-photonic devices.