Polarization-independent slow light in annular photonic crystals

Abstract

A photonic-crystal waveguide hosted in an annular photonic crystal is demonstrated theoretically to realize polarization-independent slow light. Through an appropriate set of design parameters, overlapping regions with constant group index and low group-velocity dispersion for both the transverse-electric and transverse-magnetic polarizations can be achieved in the common frequency regime of the waveguide modes. Assuming parameters for silicon and air, an optimal structure with group index of 50 and bandwidth of ∼0.1% is found theoretically for polarization-independent slow light in this structure.