抄録
Three-dimensional photonic crystals with the periodic variations in dielectric constant were fabricated by using stereolighography of a CAD/CAM process. The millimeter order inverse diamond structures were designed to exhibit forbidden bands in a GHz frequency range. Air spheres were arranged periodically in epoxy bulks containing titania-silica particles with high dielectric constant. The attenuation of transmission amplitude of microwave was measured by using horn antennas and network analyzer. The samples exhibited a common energy gap for Γ-X <100>, Γ-K <110>, Γ-L <111> directions in the microwave band of 9.2-10.8 GHz. The obtained results fairly agreed with the theoretical simulation of the electromagnetic wave propagation through photonic crystals. This result suggests the complete band gap formation in all directions. Alumina spheres were implanted into air gaps of crystal samples as structural defects. Localized modes were formed at the resonant frequency of the dielectric defects in the band gap.
