Photonic band gap of two-dimensional triangular photonic crystals with broken structural and rotational symmetries

Abstract

Three deformed and two rotational structures are constructed to study the effect of structural and rotational symmetries on the gap widths of E- and H-polarization bands in photonic crystals. The band structures and field patterns of a triangular lattice of hollow tellurium (Te) rods are calculated using the plane-wave method. The H-polarization band gaps are strongly affected by the interaction between the fields of the rods as the rods are deformed and affected by the reduction in the rotational symmetry as whole rods are rotated. Only the shapes of the rods affect the E-polarization band gaps as the rods are either deformed or rotated. Moreover, H-polarization modes determine the absolute photonic band gap (PBG) width as the rods are rotated, whereas E-polarization modes determine the absolute PBG width as the rods are deformed.