Mirror effect at the Brewster?s angle in semiconductor rectangular gratings

The Green's functions of microstructured rectangular gratings, and the electric field for a non-local susceptibility are given in explicit form. A very broad energy band with reflectivity almost one is shown by model calculation for a strongly diffractive grating when the angle of incidence of the light is very close to the Brewster’s angle of the equivalent slab, and the grating thickness is about one light wavelength. The physical origin of this interesting effect is completely explained for the first time as an interplay between grating resonances and surface waves. In the energy range from infrared to ultraviolet, the ratio between band width DE and band edge energy Eo scales as DE/Eo=Lx/d, where Lx is the lateral dimension, and d is the periodicity of the grating. The easy tailoring of this effect should be promising for optoelectronic and photonic large band device applications.