Research On Sensors Based On Surface Plasmon Resonance

The main work of this paper is to study sensor based on surface plasmon resonance(SPR). The principle of the SPR sensor is surface plasma wave exhibits extremely high sensitivity to the refractive index of the surface layers above the interface—supporting metal films and the test target. For its many advantages,such as high sensitivity,fast and reliability,sensors based on SPR have been widely used in biosensing,mechanical,chemical analysis,environmental monitoring and other areas.With the fast development of industrial technology, new sensors on better sensitivity,more integrated and more portable is very important.The goal of this project is to improve the perforence of sensors based on SPR.There are many obstacles restrict the development of sensor base on SPR,such as theoretical analysis, structural design and application. Our work will focus on these aspects. This thesis describes the basic nature of the surface plasmon wave and the excitation conditions of surface plasmon resonance in detail,introduce several SPR sensor’S coupling structure and different methods to detect the signal. Theoretical analysis indicate that the phase detection has more advantages over the others in sensitivity,however,we have to face the problem in miniaturization and integration. The structure of the SPR sensor is "prism-metal film-measured layer", device parameters is set according to the results of optimization by using the MATLAB.A measurement system of refractivev index of gas based on SPR sensor and phase detection is seted.The formula of RIA is derived from the variation of the phase difference between P and S polarization components of the measurement signal versus that of the reference signal is almost linear with RIA changes.A heterodyne interference optical path is built and the SPR sensor with self-adaptive structure for angle shift is applied.the self-adaptive sensor is one of most important device in this design,this application reduces the measurement error by an order of magnitude and improves the sensitivity.The measurement system is used to complete the detection of the refractive index of the air and carbon dioxide gas.The comparison experiments with the theory equations show that the accuracy reaches the expected. A RIA measurement system of liquid based on SPR is built.The experimental results of measuring glycerine solution refractive index are consistent with the theoretical analysis, and agree with the results of another method. The RIA detection system can be widely applied in corresponding fields.