Study Of High-sensitivity Sensing Technology Based On Attenuated Total Reflection Surface Wave

With development of social economy,the environment problems have become more and more serious and the air pollution is an important aspect of environmental pollution.When the concentration of certain trace gases such as sulfur dioxide,nitrogen dioxide,carbon monoxide and so on becomes high in the air,it will damage our body healthy.Therefore,detecting these trace gases has become more and more important.In recent years,How to detect these trace gases has been become an important research direction in current science research.Surface plasma resonance(SPR)is an optical phenomenon about evanescent field,which can be used to detecting concentration of analyte by measuring refractive index of material on the surface of the metal layer.In the last decades,the SPR technology has been widely applied in many fields such as medical diagnosis,food security and environment monitoring because of its advantage in real-time monitoring,high sensitivity,high precision and high limit of detection.This paper is based on the SPR theory by using attenuation total reflected light excitation method.A multilayer film structure based on prism coupler was innovatively constructed.Then the Fresnel’s equations of this multilayer film structure are well computed by transition matrix analysis method and the relationship between reflectance spectrum and concentration of analyte was obtained.Finally,a series of research experiment has been conducted by this structure which has been machined.The main content of this paper is as follows.(1)A planar multilayer film structure which based on the coupling between the waveguide mode(WGM)and the surface plasmon polariton(SPP)has been constructed.This multilayer film structure which is a Kretschmann configuration mainly consisted of prim/Ag/SiO2/ZrO2/sensing layer.(2)In order to verify the experimental detection capability of this structure.A series of theoretical simulation have been conducted by using the data from different concentration of salt solution.Then an experimental system is innovative constructed base on this structure.The experiment shows that experimental results have good correlation with those from theoretical calculation and there is also a good linearly relation between the concentration of the salt solution and the resonance angle with the linearly correlation coefficient R2 reaching to 0.9988.(3)The capability of detecting gases such as sulfur dioxide has been computed from theory.