In this manuscript, a plasmonic refractive index sensor with two sequential ring resonators is presented. Due to the dual-band unidirectional reflectionless light propagation phenomena, both the sensitivity and figure of merit are improved. The finite-difference time-domain (FDTD) method is used to simulate the structure numerically. Moreover, the device is investigated analytically, using the coupled-mode theory (CMT). A good agreement between the analytical and numerical results is observed. The proposed device indicates a high sensitivity of ∼1000 nm/RIU, a significant figure of merit of 133 RIU⁻¹, and a large quality factor of 132.8 for sensing different materials with the refractive indices of n = 1, 1.2, 1.3, 1.4, 1.5, and 1.6. Also, the presented structure is investigated as a temperature sensor in which the sensitivity to the temperature changes is obtained as 0.41 nm/°C.

在此手稿中，提出了具有两个顺序环形谐振器的等离激元折射率传感器。由于双波段单向无反射光传播现象，灵敏度和品质因数均得到改善。时域有限差分法（FDTD）用于数值模拟结构。此外，使用耦合模式理论（CMT）对设备进行了分析研究。观察到分析结果和数值结果之间的良好一致性。拟议中的设备显示出〜1000 nm / RIU的高灵敏度，133 RIU ^-1的显着品质因数以及132.8的大品质因数，可用于感测折射率为n的不同材料。 = 1、1.2、1.3、1.4、1.5和1.6。另外，研究了所提出的结构作为温度传感器，其中对温度变化的灵敏度为0.41nm /℃。