Photonic band gap in the visible range in a three-dimensional solid state lattice

We report on the photonic band gap effect in the visible range in a three-dimensional dielectric lattice formed by closely packed silica spherical clusters and by interconnected cavities filled with various liquids. The spectral position and the spectral width of the optical ''stop-band'' depend on the lattice period and on the relative sphere/cavity refraction index n. The stop band peak wavelength shows a linear dependence on n. Transmission characteristics of the lattice have been successfully simulated by numerical calculations within the framework of a quasicrystalline approximation.