2D hexagonal resonant grating filters performances: Measurement and modelling

Resonant grating filters (RGF) are basically a planar waveguide with a sub-wavelength periodic structuration that transmits and reflects light specularly. It is well known that the reflectivity of such a structure presents anomalies (or peaks) versus the wavelength, generated by the coupling and out-coupling of a mode of the waveguide. These peaks can be tailored in order to create free-space narrow band reflection filters. The fabrication processing and the demonstration of high performance, narrow band filters using 2D lattices to exhibit nearly polarization independent behavior have already been reported.