Two-dimensional grating for narrow-band filtering with large angular tolerances

• DOI: 10.1364/oe.24.014974
• Publication Date: 2016-06-23T16:05:16Z
• Authors: Evgeny Popov; Anne-Laure Fehrem...; Yoann Brûlé; Guillaume Demésy; Philippe Boyer
• Keywords: Guided-mode resonance; Rigorous coupled-wave analysis

A two-dimensional periodic sub-wavelength array of vertical dielectric cylinders on a glass substrate is studied numerically using three different electromagnetic approaches. It shown that such structure can present narrow-band spectral resonance characterized by large angular tolerances and 100% maximum in reflection. In particular, two-nanometer bandwidth the reflectivity stays above 90% within angles incidence exceeding 10 degrees for unpolarized light. Bloch modal analysis shows these properties are due to excitation hybrid mode created guided-like localized cavity mode. The first one collective effect array, while second comes from mode(s) single step-index fiber.