Octagonal photonic quasicrystal based add-drop filter

This paper presents a numerical study and design of a ring resonator add-drop filter based on a photonic quasicrystal. The design consists of an octagonal lattice of high index (n = 2.9) dielectric rods in air. This structure is known to possess a complete photonic bandgap for the TM polarisation over a wide range of refractive indices of the rods. The FDTD method is used to calculate the spectral response of a quasicrystal, waveguides, resonators and add-drop filter based on these building blocks. The proposed structure demonstrates a reasonable efficiency, opening the possibility for further optimization and practical realization.