Over-Coupled Mode Based on Metamaterial Absorber for Enhanced Molecular Detection

In this paper, we developed an over-coupled (OC) mode metamaterial absorbers (MA) for enhanced molecular detection. First, we established a theoretical framework for MA-molecule coupling system based on temporal coupled model theory. Based on the theoretical framework, we find that the MA in OC mode has strong sensitivity. Further, we verified the excellent sensing properties of the MA in OC mode through simulations and experiments. In particular, the experimental results show that the enhanced sensitivity of MA in OC mode is 6.54 times than that of conventional MA design. As a new design strategy, our work will provide new insights into the potential applications of nanophotonics including spectroscopy and sensors.