A graphene-based tunable guided-mode resonance narrowband mid-infrared filter
Abstract
We report a graphene-based tunable ultra-narrowband mid-infrared filter which can be tuned from 4.45122 μm to 4.44675 μm by tuning the Fermi level from 0.2 eV to 0.6 eV. Furthermore, the reflection bandwidth is less than 0.2 nm and the reflection rate is more than 0.55. The ultra-narrowband filter is designed based on the guided-mode resonance (GMR) effect. The shift of reflection peak is mainly caused by the change of the real part of the graphene’s permittivity. This tunable ultra-narrowband mid-infrared filter can be applied in the mid-infrared microscopy.