二氧化硫监测的光纤传感方法研究

Study on the Fiber Optic Sensing Method for Monitoring Sulfur Dioxide in Environment

提出一种用于监测二氧化硫的光纤传感方法,该方法以光化学氧化的n型多孔硅作为传感材料和蓝光发光二激管作为激发光源,通过微型光纤光谱仪测量二氧化硫气氛中多孔硅的光致发光猝灭程度,从而获取二氧化硫含量信息；依据半导体电化学和固体光谱学理论分别讨论n型多孔硅形成和二氧化硫传感的基本原理,采用红外光谱仪研究光化学氧化的n型多孔硅化学组成,并进一步开展二氧化硫光纤传感实验,证明光化学氧化的n型多孔硅在传感过程中稳定性高、可逆性好,其光致发光峰强度随二氧化硫浓度增加而减小,多孔硅荧光峰强度对二氧化硫浓度的线性响应范围为10×10^-6～10 000×10^-6,检测限为10×10^-6；可形成一种便携、全固态的二氧化硫光纤传感器.

A fiber optic sensing method for monitoring sulfur dioxide （SO2） in environment is presented. With blue LED excitation source and miniature fiber optic spectrometer,the intensity of photoluminescence peak for n-type porous silicon stabilized by photochemical method in SO2 gas is measured. By analyzing the variation of intensity,the concentration of SO2 gas can be obtained. According to theories of semiconductor electrochemistry and solid state spectroscopy, the basic principle of n-type porous silicon＇s formation and its SO2 sensing are discussed respectively. The chemical constitute of stabilized porous silicon is studied by infrared spectroscopy, and its SO2 sensing performance is also evaluated. It is shown that the photoluminescence of stabilized n-type porous silicon can rapidly and reversibly quenched by SO2 gas, and the Corresponding peak in quenching process is very stable. The result demonstrates the feasibility of the fiber optic sensing method for monitoring SO2 gas in environment.