摘要：Mid-infrared absorption spectroscopy is a powerful tool to identify analytes by detecting their material fingerprint in a label-free way, but it faces barriers on trace-amount analysis due to the difficulties in enhancing the broadband spectral signals. Here, we propose a sensing scheme based on the angular scanning of polarized light on a dielectric metagrating, and demonstrate it by numerical simulation. This approach not only indicates a series of significant signal enhancement factors over 30 times in an ultra-wide mid-infrared band, but also enables the explicit identification for various analytes, including 2D materials and trace-amount thin film samples. Our method would facilitate mid-infrared sensing for 2D materials and trace-amount analysis, and enable many new applications on non-destructive molecular identification.
