Diffraction from Highly Conducting Wire Gratings of Arbitrary Cross-section

Abstract

A theory describing the diffraction properties of highly conducting wire gratings with arbitrary cross-sections is presented. The method incorporates the surface impedance boundary condition on the field along metallic interfaces and relies on the solution of a coupled system of ordinary differential equations for finding the field between wires. The theory is exemplified numerically for different wire profiles. The numerical results for gold gratings in the resonance region are compared with those obtained from a theory valid for perfectly conducting wires. Comparisons to measurements validate the effectiveness of the developed algorithm and show that it is particularly suited for dealing with metallic gratings in the infrared region.