Three-Dimensional Complete Photonic-Band-gap Structures in the Visible

It is shown that for a simple face-centered-cubic lattice of spherical scatterers more than one complete photonic band gap (CPBG) can open and the relative gap width can be as large as $10\%$ even if the host dielectric constant ${\varepsilon }_h=1\mathrm{}$. The key is to use the spheres made out of material having a Drude-like behavior of the dielectric function, and, to tune lattice spacing appropriately to a characteristic plasma wavelength. We argue that such structures can provide CPBG structures with tunable band gaps down to ultraviolet wavelengths.