基于扫描光源的光纤气体传感系统的研究

Research on Fiber Gas Sensor System Based on Scanning Light Source

提出了一种基于窄带扫描光源的光纤气体传感系统。该系统能在多种气体共存环境下,完成对不同组分气体浓度的检测。克服了传统光纤气体传感系统在多种气体共存环境下需要多台光源进行检测的弊端,降低了工业化气体检测的成本。系统以放大自发辐射(ASE)光源为基础,结合锯齿波(STW)驱动的可调谐法-珀(Fabry-Perot)滤波器形成窄带扫描光源。针对可调谐滤波器的电容特性会引起锯齿波驱动失真的现象,提出了采用并联谐振回路的方案来解决锯齿波驱动失真的问题,保障了扫描光源工作的稳定性。实验结果表明,在乙炔和氨气混合气体的环境下,本系统可以实现对不同组分气体浓度的同时检测,检测结果误差较小。

An optical-fiber gas sensor system based on narrowband scanning light source is proposed. It can complete the concentration detection of various gases mixed in the environment. As usual, traditional fiber gas sensor system requires multiple light sources for detection when there are several different kinds of gases. By using scanning light source, the cost of industrialization gas detection can be reduced. Using an Amplified Spontaneous Emission （ASE） source as foundmental instrument, combining tunable Fabry-Perot filter driven by saw-tooth wave （STW）, narrowband scanning light is generated. As the Fabry-Perot tunable filter is a capacitive device, it can cause the linear distortion of the saw-tooth wave. Parallel resonant circuit solutions are proposed to decrease saw-tooth wave linear distortion, thus the stability of light source scanning work is guaranteed. Experimental results show that the system can detect the gas concentration of different components which are mixed with acetylene and ammonia gas. Experimental results also show low error rate.