Sensor Of Surface Plasmons Resonance Based On Muti-layers Nano Films

Surface plasmons resonance is a photoelectric resonance phenomenon under the interaction of charge oscillations in the metal dielectric interface and the incident light.The surface plasmons resonance detection technology is a new technology developed in recent years. It has advantages of high-sensitivity, real-time response and label free etc., and has been widely applied in food safety, medical diagnosis, environment monitoring, nano-photonic devices and biosensors etc. With the rapid development of a variety of detection technology, higher requirements are put forward to the sensing performance, such as the SPR resolution, sensitivity of the SPR detection system. That makes the SPR technology has become a hotspot at home and abroad.Firstly, this paper introduced the research background, research status and development trend of surface plasmon resonance sensor, and described the type of surface plasmon resonance detection, detection principle and modulation types. We analyzed the Kretschmann SPR structure deeply. Then the basic theory and the sensing characteristics of SPR were analyzed, and the calculation method and numerical simulation method of SPR theory were introduced simply.Secondly, a SPR sensing model based on porous silicon was structured. The model takes advantage of the character of porous silicon: the refractive index of porous silicon changes with the refractive index of analyte. The SPR resonance spectrum of the model was optimized. The resonance spectroscopy of the model was calculated by numerical simulation, and the Influence mechanism on the sensing performance was analyzed, which is from the structural parameters of the porous silicon layer. Then theoretical analysis and parameter optimization of the sensor structure were conducted, and the final sensor structure was established. The performance of the sensor model was analyzed by using ethylene glycol solution as the sample.Finally, a surface plasmons resonance incentive model based on waveguide SPR of double dielectric layers was proposed, which is prism base-silver-dielectric layer1-dielectric layer2-analyte. Numerical simulation was conducted on the resonance spectroscopy of the double dielectric layers structure by finite element analysis method. Then the effect of the double dielectric layers on the incentive mechanism and modulation characteristics of the surface plasmons resonance was discussed. Similarly,taking the ethylene glycol as the sample detected, the sensor sensitivity, resolution and quality factor Q were analyzed. The results demonstrated the feasibility of the proposed model, which provides a theoretical reference for the design of sensing system with high resolution and high Q value.