摘要
利用内表面镀铝空芯光纤在紫外-可见光波段的低损耗特性,结合宽光谱光源和光谱仪,搭建了紫外-可见光波段的吸收谱式气体传感系统.理论研究了系统参数对吸光度的影响,对影响系统信噪比的因素进行了优化.实验测量得到了系统光源的发散角色散曲线,研究结果表明在宽谱光源下,为获得准确的损耗或吸收特性,需要根据系统光源发散角的色散特性对测试结果作相应的补偿.在255nm波长带对不同浓度甲苯气体进行了测量,得到了线性的甲苯浓度-吸光度曲线,精确度可达ppm量级.该传感系统搭建方便,测量迅速,对于在线传感监测及多波长测量具有很好的应用前景.
A spectroscopic gas sensing system is established based on the low-loss ultraviolet hollow fiber inner-coated with aluminum film.Theoretical analysis is made for dependence of the gas absorbance on system parameters,and factors that affect system signal-to-noise ratio are optimized.The results show that loss spectrum is dependent on the divergence angle of input light beam.A modified calculation model is proposed based on the experimental data for the light beam of the sensing system.The dispersion property for the divergence angle should be taken into consideration for accurate detection for the loss and absorption properties in the spectroscopic gas sensing systems.Absorption of toluene gas with various concentrations is measured at the wavelength band of 255nm,and the absorption shows good linear relationship with toluene concentrations,with accuracy of ppm level.
出处
《复旦学报（自然科学版）》
CAS
CSCD
北大核心
2013年第3期386-393,共8页
Journal of Fudan University：Natural Science
基金
国家自然科学基金资助项目(60971014)
关键词
光纤光学
传感系统
紫外吸收光谱
空芯光纤
发散角
fiber optics
sensing system
UV absorption spectrum
hollow fiber
divergence angle
