Computer simulation of electromagnetic transmission through perfectly conducting plate with subwavelength apertures

The study of electromagnetic transmission through a metallic plate with apertures has been investigated for a long time. However, it is one of the important current issues in optics. The small aperture of a metal-coated probe makes possible high resolution beyond the refraction limit (Ohtsu, M. and Hori, H., "Near-field Nano-optics: From Basic Principles to Nano-Fabrication and Nano-Photonics", Kluwer Academic Plenum Publishers, 1999). The extraordinary enhancement of the optical transmission through subwavelength apertures in metal films has been observed (Ebbesen, T.W. et al., Nature, vol.391, p.667-9, 1998). We perform computer simulations of the electromagnetic transmission through a perfectly conducting plate, which has infinite area, with subwavelength apertures. The surface integral equation method is employed to perform the computer simulation. The apertures which are parallel to the incident electric field have more influence on the field distributions than the apertures which are perpendicular to the incident electric field.