Resonant scattering of light by an open cylindrical cavity ruled on a highly conducting flat surface

Electromagnetic scattering from a groove in the form of an open cylindrical cavity ruled on a planar, highly conducting flat surface, is analysed by means of an integral method based on Green's theorem and an impedance boundary condition. We consider that the groove has circular cross section and that the center of the circle is located below the planar surface. In this situation, the groove behaves as an open cavity that provides a mechanism for the existence of s and p resonances. These resonances, which show as sharp dips in the curves of scattered intensity versus incident wavelength, give strong enhancement of the local field intensity inside the cavity and near the surface. (C) 1999 Published by Elsevier Science B.V. All rights reserved.