Abstract
Optical near-field in the aperture in the thick metallic screen is analyzed numerically by the three-dimensional volume integral equation with Generalized Minimum Residual Method. Numerical results have been confirmed by the invariance of the results of the discretized size and reciprocity. The dependence of the scattering cross section on the thickness of the screen have been calculated. It is found that near-field distribution around the small aperture is a slightly different from Bethe's results.