Total absorption of light by a sinusoidal grating near grazing incidence

Abstract
A heretofore unknown total absorption phenomenon on a diffraction grating has been demonstrated both theoretically and experimentally. It occurs only in a series of six special conditions, namely, groove shape, angle of incidence, groove frequency, depth modulation, polarization, and metal surface. None of the classical explanations for grating anomalous behavior seems to correspond to this case.