Fabrication of a graded-wavelength guided-mode resonance filter photonic crystal

The authors report on the fabrication and characterization of a guided-mode resonance filter whose spectral reflectance features vary in a linear fashion as a function of position on the filter. This device was fabricated using nanoreplica molding in conjunction with a linearly graded TiO₂ thin film deposition. The magnitude of gradation of the thin film was approximately 85 nm over a distance of 26 mm, which resulted in the spectral location of the primary reflection feature of the filter to be nearly linearly graded spanning a range of 798-909 nm across the 26 mm surface.