Geometrical optics approximation for plane-wave scattering by a rectangular groove on a surface.

Abstract

Rigorous solution of plane-wave scattering by a groove based on electromagnetic theory will be time-consuming if the groove width is much larger than the illumination wavelength. To accelerate the computation, an approach based on geometrical optics approximation is developed here. The incident beam is split into several parts during reflection and refraction. Contribution of every part is superposed to obtain the electric field at the interface between the groove and air, with which diffraction theory is utilized to calculate the far-field scattered light. Results demonstrate that the approach is capable of accurately calculating plane-wave scattering by rectangular grooves with large widths in a time-efficient manner, which can be beneficial for further inverse scattering problems.