Photonic band gaps of two-dimensional square-lattice photonic crystals based on 8-shaped scatters

A novel photonic crystals (PhC) based on 8-shaped scatters with two-dimensional (2-D) square-lattice is presented. By employing the MIT photonic bands (MPB), the relationship between the structural parameters of the PhC and the properties of photonic band gaps (PBG) are investigated. The calculation results of 8-shaped scatters with 2-D square-lattice demonstrate that the reduction of scatters’ symmetry can produce larger number of PBG and broaden the width of PBG only for TM mode, and reversely for TE mode. The peculiarity would meet the distinguish employment of different mode. By optimizing the structural parameters, the maximum absolute PBG 0.1028(ωa/2πc) at R = 0.3, ɛr = 11.56, θ = 45° is obtained and six absolute PBGs is got at R = 0.3, θ = 115°, ɛr ∈ [32.3, 33.5].