High spatial resolution imaging in a clipping Kagomé lattice photonic crystal

Abstract In this paper, a two-dimensional Kagome lattice photonic crystal (PC) made of GaAs ( ɛ = 12.96) dielectric rods in air is considered. This Kagome lattice PC has an effective refractive index n eff = −1 at a low normalized frequency ω = 0.187 × 2 πc / a . Imaging quality and the capability of the super-resolution of two point sources are studied for a superlens made of such PC structure. In order to achieve a high quality image and to improve the spatial super-resolution of two sources, a clipping Kagome lattice PC is designed. Results simulated by finite-difference time-domain method show that imaging quality and super-resolution of two sources can be enhanced greatly as the perfect Kagome lattice structure are superseded by the clipping Kagome lattice structure. Coupled-mode theory analysis gives an explanation why the clipping structure is superior to the perfect one for both the imaging quality and the capability of the super-resolution of two sources. This clipping Kagome lattice PC structure would be widely used in optical devices and integrated circuit.