Bidirectional tunable nano-film absorber based on Fabry-Perot resonance incorporating polymer-dispersed liquid crystal

A perfect bidirectional dynamic tunable absorber working in the near-infrared based on an asymmetric FabryPerot resonance in a thin film dielectric-metal multilayer structure is proposed. Perfect narrowband absorption occurs at the wavelength of 1023 nm (full width at half-maximum, 13 nm) when light is normally incident on the surface covered with a silver film with a saturation voltage applied to polymer-dispersed liquid crystal (PDLC). Illumination from the opposite direction results in ultra-broadband absorption (98.91% absorption averaged over 764-2476 nm). The narrowband absorption can be dynamically tuned in the 1023-1056 nm range via PDLC modulation. Furthermore, the excellent angular sensitivity of the narrowband absorption, as well as the good angular and polarization tolerances of the broadband absorption are demonstrated.

Automated summary

This study proposes a bidirectional dynamic tunable absorber based on a thin film dielectric-metal multilayer structure, which exhibits excellent absorption performance in the near-infrared range. The narrowband absorption can be dynamically tuned via PDLC modulation, and the angular and polarization tolerances of both narrowband and broadband absorptions are demonstrated.