Weakly coupled hybrid guided mode resonance optical transmission filter

Abstract

Hybrid metal-dielectric guided mode resonance devices have an advantage over the all-dielectric guided mode resonance device for having a thin metal grating conductive layer that can be used as an electrode for tunable applications. In this work, we investigate the coupling between the waveguide mode and surface plasmons of the gold nanoslits grating in the hybrid guided mode resonance filter. It is shown that the coupling between the waveguide mode and surface plasmons can be engineered by increasing either the thickness of the low index of the refraction spacing layer or the thickness of the high index of the refraction waveguide layer. Therefore, a narrow spectral linewidth and a high finesse of hybrid guided mode resonance filters can be obtained by increasing the thickness of the low index of the refraction spacing layer or the thickness of the high index of the refraction waveguide layer. A hybrid guided mode resonance transmission filter with a narrow spectral linewidth of 2.8 nm is designed at the 1660.2 nm center wavelength.