Зонная структура фотонного кристалла с симметрией решетки клатрата SI34

The band structure of a photonic crystal with the clathrate Si-34 lattice comprising 34 lattice sites in the unit cell is studied. The lattice is found to have a large isotropic band gap for a wide range of permittivity. The relationship between the photonic band isotropy and the permittivity is deduced.