基于微加工工艺的光纤消逝场传感器及其长度特性研究

Research on the fiber-optic evanescent field sensor based on microfabvication and the effect of fiber length on its properties

用硅光刻工艺和二氧化硅湿法腐蚀工艺制作了针状封装结构的光纤消逝场传感器.该结构的传感器体积小、试剂消耗量少,减轻了测量过程中光纤的变形,密封的结构可以有效地防止传感器受到污染.从理论和实验角度研究了不同长度的光纤消逝场传感器的测量结果,分析了传感光纤长度对传感器吸光度的影响,指出随着传感器传感光纤长度的继续增加,会使后续增加的传感光纤对传感器灵敏度的贡献越来越小.

Evanescent wave fiber-optic sensors（EWFS）with acicular encapsulation were fabricated using silicon photolithography technology and silica wet-etching technology.This type of EWFS is small in size,consumes little reagent,suffers less from deformation during the detection process and also protects the sensors from pollution.The results obtained from the EWFS with different sensing fiber lengths were studied.The effect of the fiber length on the sensor＇s absorbance were analyzed theoretically and experimentally.It was shown that the properties of the EWFS could be improved greatly by choosing suitable length of the sensing fiber,and the contribution of unit length of sensing fiber to the absorbance becomes less as the sensor＇s total length becomes longer.