采用严格耦合波方法研究了普通棱镜耦合的表面波传感器与光栅辅助的表面波传感器的传感特性。设计了工作在1550 nm处的一维光子晶体与光栅的材料 参数与结构参数。光栅的深度为20 nm,周期为524.6 nm,占空比为0.5。模拟计算表明,光栅的引入导致双共振峰的出现,表面波的模式出现分裂。当外界 折射率变化时,两个共振峰向相反的方向移动。利用双共振峰的这种特性进行传感,可以使光栅辅助表面波传感器的角度灵敏度提高到普通棱镜结构 表面波传感器的3倍以上。

An ordinary prism coupling surface waves (SW) sensor and grating-assisted SW sensors are studied using rigorous coupled-wave-analysis method. The material parameters and structural parameters of the one-dimensional photonic crystal and grating are designed, which works under 1550 nm. The depth of grating is 20 nm, the pitch is 524.6 nm, and the duty cycle is 0.5. Simulation shows that grating leads to the emergence of dual-resonance dip, and the surface mode is splitted. The use of double resonance dip characteristics can improve sensitivity of the perspective of an ordinary prism structure SW sensor more than 3 times.