Performance Optimiezd Of Surface Plasmon Resonance Sensors

Surface plasmon resonance(SPR)sensors are optical sensors which have a kind of high performance,and a good application prospect.In this paper,the performance of the traditional Kretschmann structure SPR sensors is studied,the main performance parameters of the SPR sensors is simulated.Finally,we succeed to enhance the figure of merit(FOM)of the SPR sensors by adding the absentee layer or porous silica film.By adding an absentee layer on the top of the metallic layer,the FOM of SPR sensors with Kretschmann configuration was enhanced,without changing the resonance angle and the reflectance at the resonance angle.Comparing with a traditional SPR sensor,"the FOM of the SPR sensor with an absentee layer composed of either 1367 nm thick KC1 or 235 nm thick Si3N4 can be improved by 5.53%or 11.41%.The enhancement of FOM should be attributed to the faster decreasing of the full width at half maximum than the sensitivity after an absentee layer was applied in the SPR sensor.In this thesis,the effect of the thickness and porosity of the porous silica film on the performance of the sensors was analyzed.The results indicated that the FOM of a SPR sensors can be enhanced by using a porous silica film with low refractive index.Particularly,the FOM of a SPR sensors with a 40 nm thick 90%porosity porous silica film whose refractive index is 1.04,was improved by 311%compared with that of a traditional SPR sensors.Furthermore,it was found that the decrease in refractive index or the increase in thickness of low-refractive-index porous silica film can enlarge the FOM enhancement.It is believed the proposed SPR sensors with low-refractive-index porous silica film will be helpful for high-performance SPR sensors development.