一种可见光波段气体传感器的设计与研究

为了设计一种性能优越的气体传感结构，提出一种亚波长介质光栅/电介质/金属衬底混合波导结构，基于导模共振效应，在反射光谱中形成4个窄带共振缺陷峰。选用多孔硅作为波导层，基于多孔硅的折射率可调特性，通过观察共振波长的漂移实现样本气体浓度的动态监测，分析结构的传感特性。结果表明，3个窄带共振峰的灵敏度分别为300，350，400 nm/RIU，品质因数分别可以达到120，152.2，307.7/RIU，检测精度高，皆可用于气体传感。

Design and analysis of a visible light band gas sensor

In order to design a gas sensing structure with superior performance, a hybrid waveguide structure consisting of a subwavelength dielectric grating, a dielectric layer and a metal substrate was proposed. Based on the guided mode resonance, four narrow-band resonance defect peaks were formed in the reflection spectrum. Porous silicon was used as the waveguide layer. Based on the refractive index tunable properties of porous silicon, the structure can realize the dynamic monitoring of sample gas concentration by observing the drift of the resonance wavelength, and the analysis of sensing characteristics of the structure. The results illustrate that the sensitivity of three narrow-band resonance peaks are 300, 350, 400 nm/RIU respectively. And the figure of merit can reach 120, 152.2, 307.7/RIU respectively.The structure has a high detection accuracy and can be used for gas sensing.