Towards athermal organic-inorganic guided mode resonance filters

Abstract

We demonstrate guided-mode resonance filters featuring an amorphous TiO₂ layer fabricated by atomic layer deposition on a polymeric substrate. The thermal properties of such filters are studied in detail by taking into account both thermal expansion of the structure and thermo-optic coefficients of the materials. We show both theoretically and experimentally that these two effects partially compensate for each other, leading to nearly athermal devices. The wavelength shift of the resonance reflectance peak (< 1 nm) is a small fraction of the peak width (∼ 11 nm) up to temperatures exceeding the room temperature by tens of degrees centigrade.