Multi-spectral programmable absorbers

TL;DR

This paper presents a multi-spectral programmable perfect absorber using phase-change materials, enabling tunable infrared absorption at multiple wavelengths through temperature control.

Contribution

It introduces a novel design combining Ge2Sb2Te5 and VO2 NPs for reconfigurable, large-scale, polarization-insensitive infrared absorption.

Findings

Achieved >90% absorptance at four IR wavelengths

Tunable from 1906 to 2960 nm via heating

Reconfigurable and polarization-insensitive design

Abstract

We designed and demonstrated a multi-spectral programmable perfect absorber that exploits two different phase-change materials. This programmability is possible by resonantly coupling two phase change materials, a Ge2Sb2Te5 layer to vanadium dioxide nanoparticles (VO2 NPs). The perfect absorption is attributed to the coalescence of gap plasmon modes excited between the NPs and waveguide cavity-like modes excited between the film and the NPs. The absorptance peak (>90%) can be tuned to four different infrared (IR) wavelengths from 1906 to 2960 nm by heating the structure to different temperatures. The perfect absorber is reconfigurable, lithography-free, large-scale, polarization-insensitive omnidirectional. Our strategy opens a new path for programmable infrared photonics.