一种谐振腔嵌入银纳米棒的表面等离子体激元传感器

Surface plasmon polariton sensor with resonant cavity embedded in silver nanorods

针对现阶段表面等离子体激元(SPP)传感器存在灵敏度低、结构制造复杂等问题,提出了一种由金属-绝缘体-金属波导和嵌入银纳米棒的谐振腔构成的高灵敏度、可调谐的SPP传感器。采用时域有限差分法对所设计传感器的光传输特性及传感特性进行了理论研究。仿真结果表明:当谐振腔引入或者不引入银纳米棒时,传输谱在500~3500 nm波长范围会呈现4个或者2个谐振峰;该结构的折射率灵敏度高达2116.72 nm/RIU,品质因数为27.503;通过对谐振腔填充乙醇,该结构可实现对环境温度的测量,温度灵敏度可达0.982 nm/℃。

Aiming at the problems of low sensitivity and complex structure of surface plasmon polariton(SPP)sensor at the present stage,a highly sensitive and tunable SPP sensor composed of metal-insulator-metal waveguide and a resonant cavity embedded with silver nanorods is proposed.The optical transmission characteristics and sensing characteristics of the designed sensor are studied by using the finite difference time domain method.The simulation results show that the transmission spectrum will show four or two resonance peaks in the wavelength range of 500~3500 nm when the silver nanorods are introduced into the resonator cavity or not.The refractive index sensitivity of the structure is as high as 2116.72 nm/RIU,the quality factor is 27.51.By filling the cavity with ethanol,the structure can measure the ambient temperature,and the temperature sensitivity can reach 0.98 nm/℃.