Band structures of three-dimensional photonic crystals consisting of dielectric spheres: a plane-wave approach

Using the plane-wave method, we calculate the band structures and transmission characteristics of the three-dimensional fee photonic crystals. For a SiO2 opal photonic crystal, we calculate the energy spectrum and the transmission feature of electromagnetic waves along the [111] direction using both the plane-wave method and the transfer-matrix method, the obtained results are consistent with each other. For a full band gap studies of the inverse-opal structure, the convergence effect in the plane-wave method on the calculation is discussed. For an fee lattice of core-shell sphere, it is shown that the relative L-gap width of a suitable coating of dielectric spheres of a lower dielectric material can increase by 50% as compared with that of homogeneous high - dielectric spheres. We also find that the optimum radius ratio between interior and entire spheres is 0.69.