Spectral Features of Guided Mode Resonant Filter With Two-Dimensional Crossed Grating

Spectral responses of guided mode resonant filter (GMRF) with two-dimensional (2-D) crossed grating are comprehensively investigated in this paper. Commercially available software based on the rigorous coupled wave analysis method is used to design and optimize the device as well as to calculate the reflectance spectra. There exist two peak resonances under normal incidence and the two wavelengths generate two pairs of resonant bands as varying the incident angle from 0° to 30° (-30°) for both S- and P-polarization. The resonant positions of the split branches shift with the grating period along the x-axis; whereas the other pair of bands, which are degenerated for both normal and oblique incidences, are controlled by the grating period along the y-axis. The physical mechanism of the spectral features is also analyzed in detail by means of the wave vectors. Results and methods provided herein enable a clear understanding of the physical properties of the filter with 2-D crossed grating, which are highly beneficial for studying new features of 2-D GMRF.