基于异丙醇填充和游标效应增敏的氢气传感器

Hydrogen Sensor Based on Isopropanol Filling and Vernier Effect Sensitization

采用高热光系数的异丙醇和平行连接结构,使基于Pt-WO_3敏感膜的法布里-珀罗氢气干涉仪灵敏度得到了大幅度提升。传感器的异丙醇腔由孔径126μm空心光纤和端面镀有银膜的单模光纤组成,结构紧凑且稳定。氢敏测试结果表明:干涉仪在0~2%(vol%)氢气浓度范围内的灵敏度为1.746 4 nm/%,响应速度快,重复使用性好。将两个具有微小腔长差的干涉仪通过2×2的耦合器平行连接,利用光学游标效应实现灵敏度放大,组合后的传感器达到了15.729 3 nm/%的高氢气灵敏度,并且两个干涉仪本身可以达到温度自补偿,大幅度降低了温度交叉敏感度。本文为制备灵敏度高、低成本、适用范围广的氢气传感器提供了一次有益的探索。

The sensitivity of the Fabry Perot hydrogen interferometer based on Pt-WO3 is greatly improved by using isopropanol with high thermal optical coefficient and parallel connection structure.The isopropanol cavity of the sensor is composed of a hollow fiber with an aperture of 126μm and a single-mode optical fiber coated with silver film on its end face.The results of hydrogen sensitivity test show that the sensitivity of the interferometer in the range of 0~2%(vol%)hydrogen concentration is 1.7464 nm/%,fast response and good reusability.Two interferometers with small cavity length difference are connected in parallel through a 2×2 coupler,and the sensitivity is amplified by using the optical vernier effect.The combined sensor has a high hydrogen sensitivity of 15.7293 nm/%and the two interferometers can achieve temperature self compensation,which greatly reduces the temperature cross sensitivity.This research provides a useful exploration for the preparation of hydrogen sensors with high sensitivity,low cost and wide application range.