理论研究了一种手性双层等离激元超表面的圆二向色性光谱传感效应。 通过分析其电磁场的空间分布发现,这种由人工结构增强的手性响应的产生归因于等离激元超表面狭缝的局域 等离激元与两层超表面之间的耦合作用,且这种结构的圆二向色性透射光谱与圆共偏振透射光谱的变化对生化 层折射率的变化具有不同的响应。在合适的结构参数下,圆共偏振透射光谱以及圆二向色性透射光谱传感灵敏 度最大分别能够达到109 nm/RIU、111 nm/RIU。该人工手性结构具备共偏振光谱和圆二向色性光谱传感功能, 在新型生化传感器件领域具有潜在的应用价值。

The circular dichroism spectral sensing effect of a chiral double-layer plasmon metasurface is investigated theoretically. By analyzing the spatial distribution of the electromagnetic field in the structure, it can be found that the enhanced chiral resonance response of the artificial structure is due to the local plasmon resonance in the slit and the coupling effect between two metasurfaces, and the circular dichroism transmission spectrum and co-polarized transmission spectrum of this structure respond differently to the refractive index changes of the biochemical layer. Under proper structural parameters, the sensitivity of circular co-polarized spectrum and circular dichroism spectrum can reach 109 nm/RIU and 111 nm/RIU, respectively. It is shown that the artificial chiral structure has the functions of co-polarized spectrum and circular dichroism spectrum sensing, and has potential application value in the field of new biochemical sensor devices.