Optical transmission properties of perforated metal films in the middle-infrared range

We experimentally studied the enhanced optical transmission of perforated silver films in the middle-infrared region. The optical transmission properties of the samples with classical inductive frequency selective surface structures are also affected by both the periodicity and the aperture shape. Our results indicate that the physical operating mechanisms are the same for the plasmon crystal and the frequency selective surface, and both surface plasmon polaritons due to the periodicity and waveguide modes that are present in single holes have effect in the optical transmission enhancement.