Abstract

We compare solutions to the problem of electromagnetic wave scattering by perfectly conducting, rectangular grooved gratings by using several scalar theories and several vector theories. The period of the gratings is on the order of the wavelength. Parameters of the grating, such as the width and depth of the grooves and the period, are varied with respect to the wavelength. The angles of incidence of the incoming plane wave are also varied. As these parameters are changed, the magnitude and phase of the diffracted orders calculated from the scalar approach are compared against the electromagnetic solution. The purpose of this comparison is to determine the range of validity for the scalar solution. For geometries where the scalar solution is poor, it may be possible to determine correction factors to improve it. Insight gained from this study may be applicable to the analysis of more complex gratings and grating-like structures.

© 1990 Optical Society of America