Modularized control of broadband surface-enhanced infrared absorption spectroscopy realized in over-coupled metasurfaces

We propose a modular designed over-coupled (OC) metasurface for the broadband surface-enhanced infrared absorption spectroscopy (SEIRAS) by analyzing the combined properties in the far field and near field.The customized sensors can independently modify the coupling mode, the resonance frequency, and the coupling efficiency by adjusting the vertical and horizontal structures and hybrid dielectric layers of the metasurface, respectively.Based on the independent regulation of the sensor properties, the influence of the detuning properties, the level of OC coupling, and the coupling efficiency of the signal amplification can be clearly presented through the single variable-controlling approach.These design principles are universal for customized sensors and herald possibilities for machine-learning-aided surface-enhanced infrared absorption (SEIRA) biosensing.