Polarization-independent dislocation modes in photonic crystals

Abstract

Recently, gapless dislocation modes along the synthetic translation dimensions are proposed in two-dimensional photonic crystals. However, gapless dislocation modes are specific to either transverse magnetic or transverse electric polarization, hindering their utility in polarization-independent optics. In this work, we achieve polarization-independent dislocation modes in the crossing of gapless dislocation modes of two polarizations. The frequencies of TM and TE polarized dislocation modes change with the translation parameter. By selecting suitable translation parameter, we realize TM and TE polarized dislocation modes at the same frequency within a single dislocation. We not only realize dual-polarization gapless dislocation modes but also investigate their eigen field characteristics with different frequencies. Our work offers a novel strategy for developing polarization-independent topological photonic devices.