Electromagnetic wave diffractions in ceramic/polymer photonic crystals with three-dimensional diamond structure

Abstract

Three-dimensional photonic crystals with periodic variations of dielectric constant were fabricated by using a stereolithography of rapid prototyping methods. Millimeter-order epoxy lattices with diamond structure were designed to reflect electromagnetic waves by forming the photonic bandgap in GHz range. Titanium-dioxide-based ceramic particles were dispersed into the epoxy lattice to control the dielectric constant. The inverse form crystals, which have a network of air holes with diamond structure in a dielectric matrix, were fabricated as well. Microwave attenuations through the normal and inverse crystals having various lattice constants were measured by using a microwave cavity and a network analyzer. These two types of the diamond structure formed a perfect bandgap which reflects electromagnetic waves along any direction. The location of the bandgap agreed with band calculations using the plane wave propagation method.