Fabrication of a point defect photonic crystal based on diamond structure with a cavity and its microwave properties

Abstract

This paper presents a novel fabrication method for three-dimensional (3D) ceramic point defect photonic crystals. The 3D defect photonic crystal, which possesses an air cavity, has been designed by cutting a rectangular shape (3.5 mm × 3.5 mm × 7 mm) in the centre of a photonic crystal with a diamond lattice structure model (50 mm × 30 mm × 20 mm) with a lattice constant of 7 mm. Stereolithography (SL) technology was applied to fabricate resin moulds with an inverse-diamond structure incorporating the defect, and high solid content aqueous ceramic slurry was prepared and injected into the moulds. After gel-casting, drying, and high-temperature sintering, ceramic 3D photonic crystals with intact structure and minimal shrinkage were obtained. The penetration of an electric field with resonant modes of about 3 mm into the host lattice was observed by measuring the <110> direction of the samples, which resulted from the rectangular air cavity resonator. The results show that this method can be used to fabricate ceramic 3D point defect photonic crystals with a complex 3D structure.