Performance of a double-layer guided mode resonance filter with non-subwavelength grating period at oblique incidence

• Theory and design method of the non-subwavelength period GMR filter were illustrated.
• Rigorous coupled-wave analysis was used to simulate the GMR structure.
• The grating period of 750 nm was fabricated, and the resonant wavelength was 659.76 nm.
• Fabrication tolerances about fill factor and grating thickness were investigated for the non-subwavelength filter.

A double-layer guided-mode resonance (GMR) filter with a non-subwavelength grating period is proposed for light reflection at oblique incidence. A zinc oxide coated photo-resist grating GMR filter was fabricated, which exhibits good filter properties. For a transverse magnetic-polarized wave, the grating period is larger than the resonance wavelength, which will reduce the difficulties associated with pattern production. The grating structure with a 750 nm period was fabricated utilizing a low cost two-beam interference system, with resonance obtained at 659.76 nm. In addition, the fabrication tolerance concerning the fill factor and the grating thickness were discussed. The device was designed utilizing numerical methods based on a rigorous coupled-wave analysis. Our design may promote the practical application of GMR filters.