# Metamaterial Perfect Absorber Analyzed by a Meta-cavity Model Consisting of Multilayer Metasurfaces

## TL;DR

This paper models metamaterial perfect absorbers as meta-cavities formed by multilayer metasurfaces, explaining their angle independence, ultra-thinness, and field localization, and suggesting new applications.

## Contribution

Introduces a meta-cavity model for metamaterial perfect absorbers, providing a unified explanation for their key features and potential for advanced photonic applications.

## Key findings

- Absorbers behave as Fabry-Perot cavities with high Q-factor
- Model explains angle independence and field localization
- Suggests applications in sensors and quantum devices

## Abstract

We demonstrate that the metamaterial perfect absorber behaves as a meta-cavity bounded between a resonant metasurface and a metallic thin-film reflector. The perfect absorption is achieved by the Fabry-Perot cavity resonance via multiple reflections between the "quasi-open" boundary of resonator and the "closed" boundary of reflector. The characteristic features including angle independence, ultra-thin thickness and strong field localization can be well explained by this model. With this model, metamaterial perfect absorber can be redefined as a meta-cavity exhibiting high Q-factor, strong field enhancement and extremely high photonic density of states, thereby promising novel applications for high performance sensor, infrared photodetector and cavity quantum electrodynamics devices.

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Source: https://tomesphere.com/paper/1705.02681