In this paper, dispersive properties of three-dimensional (3D) photonic crystals (PCs) with diamond lattices composed of the isotropic positive-index materials and epsilon-negative materials are theoretically investigated based on a modified plane wave expansion (PWE) method. The eigenvalue equations of such structure (spheres with epsilon-negative materials inserted in the dielectric background) are deduced. It can be obviously seen that a photonic band gap (PBG), a Hatbands region, and two stop band gaps (SBGs) in the Γ-X and Γ-L directions appear, respectively. The results show that the upper edges of flatbands region can not be tuned by any parameters except for the electronic plasma frequency. The first PBG and the first SBGs above the flatbands region in the Γ-X and Γ-L directions for the 3D PCs can be modulated by the filling factor, relative dielectric constant and electronic plasma frequency, respectively. However, the damping factor has no effect on the locations of the first PBG and the first SBGs above the flatbands region in the Γ-X and Γ-L directions.
展开▼
