In this paper, we propose two kinds of composite structures based on the one- and two-dimensional (1D&2D) gold grating on a gold film for plasmonic refractive index sensing. The resonance modes and sensing characteristics of the composite structures are numerically simulated by the finite-difference time-domain method. The composite structure of the 1D gold semi-cylinder grating and gold film is analyzed first, and the optimized parameters of the grating period are obtained. The sensitivity and figure of merit (FOM) can reach 660RIU/nm and 169RIU⁻¹, respectively. Then, we replace the 1D grating with the 2D gold semi-sphere particles array and find that the 2D grating composite structure can excite strong surface plasmon resonance intensity in a wider period range. The sensitivity and FOM of the improved composite structure can reach 985RIU/nm and 298 RIU⁻¹, respectively. At last, the comparison results of the sensing performance of the two structures are discussed. The proposed structures can be used for bio-chemical refractive index sensing.

在本文中，我们提出了基于一维和二维（1D＆2D）金箔在金膜上的两种复合结构，用于等离激元折射率传感。通过时域有限差分法对复合结构的共振模式和传感特性进行了数值模拟。首先对一维金半圆柱光栅与金膜的复合结构进行了分析，得到了光栅周期的优化参数。灵敏度和品质因数（FOM）可以达到660RIU / nm和169RIU ^-1， 分别。然后，我们用二维金半球粒子阵列代替一维光栅，发现二维光栅复合结构可以在更宽的周期范围内激发强表面等离子体共振强度。改进后的复合结构的灵敏度和FOM可以分别达到985RIU / nm和298 RIU ^-1。最后，讨论了两种结构的传感性能的比较结果。所提出的结构可以用于生化折射率感测。