长周期光纤光栅气敏薄膜传感器结构优化  

Structure Optimization of Long-Period Fiber Grating Gas-Sensing Film Sensors

作　　者：徐艳平[1] 顾铮■ 陈家璧[1] 高侃[2] 

机构地区：[1]上海理工大学光电功能薄膜实验室,上海200093 [2]中国科学院上海光学精密机械研究所信息光学实验室,上海201800

出　　处：《光学学报》2006年第3期326-330,共5页Acta Optica Sinica

基　　金：上海市教委"曙光计划"(02SG32);上海市自然科学基金(03ZR14071)资助课题

摘　　要：基于三包层长周期光纤光栅模型,研究了包层表面涂覆一层溶胶凝胶气敏薄膜的长周期光纤光栅化学传感器的灵敏度Sn与薄膜光学参量(折射率n3和厚度h3)和光纤光栅结构参量(光栅周期、折变量和光栅长度)之间的关系。采用最优化数值方法,找到了获得高灵敏度所需的最佳膜层光学参量和光栅结构参量。理论计算表明,该类型传感器对膜层折射率的测量分辨率高达10-8。实验上制作了对乙醇气体敏感的传感器,并证实了传感器结构优化的必要性。Based on a triple-clad numerical model, a long-period fiber grating chemical sensor coated with the sol- gel gas-sensing films on the cladding of the fiber grating region is studied. The relation between the sensitivity Sn and the thin film optical parameters （thickness h3 and refractive index n3）, and the fiber grating parameters （the grating period, the core index modulation and the grating length） is analyzed. By using optimization method, the optimal optical parameters of thin film and fiber grating parameters are obtained to make the sensor highly sensitive. Numerical simulation shows that the sensitivity of this scheme to refractive index of the films is 10^-8. In the end a long-period fiber grating sensor sensitive to C2H5OH is fabricated, which proves the necessity of the structure optimization of the sensor.

关 键 词：导波与光纤光学 长周期光纤光栅 溶胶凝胶 气敏传感器 结构优化 

分 类 号：TN253[电子电信—物理电子学] TP212.14[自动化与计算机技术—检测技术与自动化装置]