Resonance transmittance through a metal film with subwavelength holes

An analytical theory for extraordinary light transmittance through an optically thick metal film with subwavelength holes is developed. It is shown that the film transmittance has sharp peaks that are due to the Maxwell-Garnet resonances in the holes. There are localized electric and magnetic resonances resulting in, respectively, dramatically enhanced electric and magnetic fields in the holes. A simple analytical expression for the resonance transmittance is derived that holds for arbitrary hole distribution. It is also shown that there are other types of transmittance resonances, when the holes are arranged into a regular lattice. These resonances occur because of the excitation of surface plasmon polaritons propagating over the film surface. A combination of the two kinds of resonances results in a rich spectral behavior in the extraordinary optical transmittance