Void lattice effect on the optical properties of metals

Optical properties of metals containing void lattice are theoretically investigated. Bands of localized plasmons appear in the system due to overlapping of plasma oscillation fields localized on different voids. The presence of these bands results in peculiarities in the optical spectra of the metal with void lattice: refraction and absorption indices sharply change at the frequencies close to the excitation frequency of pasmons localized on the voids and the reflection coefficient has a gap. The depth of the gap depends on the relative void volume. Numerical calculations are conducted for aluminium crystal containing the void lattice