Control of vibration-metasurface coupling at mid-infrared spectral window for inorganic thermal emitters

Coupling between light and molecular vibrational modes is dependent on efficiency of molecular absorption. Here we demonstrate how to control coupling between molecular mid-infrared absorption/emission at chemical fingerprinting spectral window and metasurface using SiO2 as the absorber/emitetr and CaF2 as a spacer to optimise strength of coupling. Use of inorganic dielectric I-spacer in Metal-Insulator-Metal (MIM) metasurface opens applications in narrow-band emitters at IR spectral window at elevated temperatures (> 350C) where polymer/organic I-spacers degrade