Thermally controlled near-infrared metamaterial absorber based on vanadium dioxide

The biggest challenge of the practical applications of metamaterial-based perfect absorbers remains on the architectural design structure to engineer a system capable to achieve a near unity absorption, large absorption bandwidth and tunable resonance frequency and absorption strength. We propose and demonstrate an active visible and near-infrared metamaterial absorber formed by a sandwich of gold square metallic patch-vanadium dioxide thin film-gold layer. It shows a high absorptance up to 86% at the external temperature stimuli of 30°C, and about 30% at 85°C in the wide wavelength range from 0.9 μm to 1.5 μm. The proposed absorber has potential applications in active thermal control of electronic, optical and thermal devices.