Analysis and Applications of One-Dimensional Periodic Dielectric Gratings under Plane Wave Excitation

摘要

In this paper we analyze the frequency response of one-dimensional periodic dielectric gratings under plane wave excitation using a vectorial modal method in combination with the Generalized Scattering Matrix Technique. A very fast and efficient CAD tool has been developed for the analysis of the scattering of such structures, which allows modifying all the electrical and geometrical parameters, as grating period, thickness, frequency, polarization and angle of incidence. We show that ideal reflection (band-stop) filters with high efficiency can be designed by combining guided-mode resonance effects in periodic dielectric gratings with antireflection effects of thin-film structures, providing a symmetrical line shape with near-zero reflectivity over appreciable frequency bands adjacent to the resonance frequency. A reflection filter example employing common dielectric materials illustrates bandwidth control by grating modulation. Moreover, it is shown that the resonance frequency of the filter can be controlled by the angle of incidence. Finally, it is shown a double-band reflection filter using a structure with two gratings with different periods, with the center frequencies determined by the resonances of the individual single-layer waveguide gratings.