针对目前位移传感器体积较大和分辨率较低的问题, 文章设计了一种面内位移检测的双层纳米光栅结构, 用耦合波理论阐述光栅的衍射性质, 使用Gsolver软件对双层光栅的上下两层光栅间隙、光栅周期、光栅占空比以及入射波长进行了优化仿真分析, 研究在各参数下, 双层纳米光栅面内位移对衍射效率的影响, 最终得到一组对位移敏感的光栅结构。仿真结果表明, 当两层光栅间隔为200 nm、光栅厚度为390 nm、光栅周期为800 nm以及入射光的波长为850 nm时, 双层光栅的光透射特性较好。可通过检测透射光强的变化来获得光栅的面内微位移。

Aiming at the problem of large volume and low resolution of displacement sensor, this paper designs a nano-grating structure for in-plane displacement detection. The coupled wave theory is used to illustrate the diffraction properties of the grating. The grating gap, grating period, grating duty cycle and incident wavelength of the two-layer grating are optimized and analyzed by Gsolver software. The effects of the in-plane displacement of the double-layer grating on the diffraction efficiency under various parameters are studied. Finally, a set of displacement-sensitive grating structures is obtained. The simulation results show that the light transmission characteristics of the double-layered grating are better when the two-layer grating gap is 200 nm, the grating thickness is 390 nm, the grating period is 800 nm, and the incident light wavelength is 850 nm. The in-plane micro-displacement of the grating can be obtained by detecting changes in transmitted light intensity.