Polarization beam splitter based on two-dimensional modified annular photonic crystals with square and triangular lattices

Abstract

We study a polarization beam splitting phenomenon in modified annular photonic crystals. The modified structures are composed of square and triangular lattices with circular and square air holes in a dielectric background in which a dielectric rod is added to each air hole. The inner dielectric rods are not located at the center of the holes and are oriented relative to the lattice axis. At first, isofrequency contours of the structures are numerically investigated for different sizes of air holes and rods, using the plane wave expansion method. The effects of additional rods are clearly demonstrated in terms of tilted contours, which is effective in the direction of flow of light for different polarizations. Finally, the finite-difference time-domain method is utilized to depict the different traveling path of two orthogonal transverse magnetic and electric polarizations.