title: Collimation effect inside complete bandgap of electromagnetic surface resonance states on a metal plate perforated with a triangular array of air holes.
abstract: In this paper the transmission properties of a metal plate perforated with a triangular array of air holes is investigated. We find that the normalized transmittivity exceeds unity within a certain frequency range under normal incidence of a Gaussian beam. Calculations and experiments indicate that the phenomenon results from the collimation effect which only occurs inside the complete bandgap of surface resonance states on the perforated metal plate. The findings present a simple approach for beam collimation.
authors.affiliation: Department of Physics, Tongji University, Shanghai, 200092, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.forename: Zeyong
authors.initials: Z
authors.lastname: Wei
authors.forename: Chao
authors.initials: C
authors.lastname: Wu
authors.forename: Hongqiang
authors.initials: H
authors.lastname: Li
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.forename: Kun
authors.initials: K
authors.lastname: Cai