基于有机聚合物的光纤气体传感器

Optical Fiber Gas Sensor Based on Organic Polymer

提出了一种有机聚合物敏感结合光波相位检测的光纤气体传感方法并进行了实验验证.利用不同浓度酸性气体作用下,有机聚合物其折射率将发生改变的特性,在光纤法布里-珀罗(Fabry-Perot,FP)腔中填充有机聚合物薄膜,通过分析光纤F-P腔输出的光谱特性,实现对酸性气体浓度高精度测量.实验结果表明,有机聚合物的折射率随被测气体浓度的增加而减小,传感器的系统灵敏度为(0.726~1.006)×10^(-2) cm/%VOL,相位灵敏度为1.276×10^(-2) rad/%VOL,浓度分辨率为0.783ppm,可应用于石油化工领域二氧化碳、硫化氢等酸性气体的高精度测量.

An optical fiber gas sensing method was proposed based on the detection of light sensitive phase of light wave combined with organic polymers and the experimental verification was given.When using different concentrations of acid gases to act on the organic polymers,the refractive index of the organic polymer will change.By filling organic polymer film in optical fiber F-P cavity and analyzing the spectral characteristics of fiber F-P cavity output,it can be realized the hydrogen sulfide gas sensing.Experimental results show that accompanied by the increasing of concentration of the gas under the test,the refractive index of organic polymer decreasing.At low concentration,a record（0.726-1.006）×10-2 cm/%VOL of system resolution is obtained,Phase sensitivity is found to be 1.276×10-2 rad/%VOL and concentration resolution is found to be 0.078 ppm.Through this test,it is proved that the possibility of gas sensing by using organic polymer.This system can be applied to high-precision measurement of carbon dioxide,hydrogen sulfide and other gases in the petrochemical field.