光波导传感元件在检测酸性气体中的应用

采用旋转甩涂法将甲基紫传感薄膜固定在特制的锡(Sn2+,Sn4+)掺杂玻璃光波导(Sn doped glass slide)表面,研究了该传感薄膜与HCl、H2S、以及SO2作用前后的可见吸收光谱的变化,并在此基础上研制了玻璃光波导酸性气体(HCl、H2S、SO2)传感元件。传感薄膜与酸性气体作用时,薄膜的颜色发生变化,从而降低薄膜对倏逝波的吸收,使传感器的输出光强度(信号)增强。本文采用流动注射法对酸性气体进行了检测。实验结果表明,在室温下,该传感元件对硫化氢气体具有明显的响应,而对相同浓度的其他酸性气体的响应相对较小,对浓度在6×10-4～2.5×10-5(V/V)的硫化氢气体具有良好的线性响应(R=0.9979,n=4),相对标准偏差(RSD)为±3.5%,具有响应快、可逆性和重复性好、容易制备、可以在室温下工作等特点。

Application of optical waveguide in the acidic gases detection

Optical waveguide(OWG)sensor is a novel sensors type with its rapid development,nowadays,It has broad development prospect because of its several advantageous over other type of sensors,such as high sensitivity,easy implementation,small size,and immunity to electromagnetic interference.In this study,The methyl violet thin film was immobilized on to tin-doped glass optical waveguide(OWG)by the means of spin coater.studied the visible absorption spectra of the thin film before and after exposed to the acidic gases(HCl、H2S、SO2),on this basis,the developed the glass optical waveguide acid gases(HCl,H2S,SO2)sensing elements.when the sensing thin film exposed to the gases,the color of the film can change and the absorption of evanescent waves can be reduced,it induced the output light intensity(signal)to increased.The sensing element shows reversible、rapid response and high repeatability.