A novel complementary grating structure is proposed for plasmonic refractive index sensing due to its strong resonance at near-infrared wavelength. The reflection spectra and the electric field distributions are obtained via the finite-difference time-domain method. Numerical simulation results show that multiple surface plasmon resonance modes can be excited in this novel structure. Subsequently, one of the resonance modes shows appreciable potential in refractive index sensing due to its wide range of action with the environment of the analyte. After optimizing the grating geometric variables of the structure, the designed structure shows the stable sensing performance with a high refractive index sensitivity of 1642 nm per refractive index unit (nm/RIU) and the figure of merit of 409 RIU⁻¹. The promising simulation results indicate that such a sensor has a broad application prospect in biochemistry.

由于其在近红外波长处的强共振，提出了一种用于等离子体折射率传感的新型互补光栅结构。通过有限差分时域方法获得反射光谱和电场分布。数值模拟结果表明，在这种新型结构中可以激发多种表面等离子体共振模式。随后，由于其与分析物环境的广泛作用，其中一种共振模式在折射率传感中显示出可观的潜力。在优化结构的光栅几何变量后，所设计的结构表现出稳定的传感性能，具有1642 nm/折射率单位（nm/RIU）的高折射率灵敏度和409 RIU ^{-1的品质因数}. 有希望的模拟结果表明，这种传感器在生物化学中具有广阔的应用前景。