Study Of Producing Method And Sensing Performance Of Surface Plasmon Polaritons

In recent years,with the efforts of many scientific researchers,the detection technology of trace substances has developed rapidly.Due to the advantages of high sensitivity,label-free,real-time monitoring,low cost and easy integration to achieve miniaturization,the sensing detection technology based on surface plasmon polaritons(SPP)resonance has been widely used in chemistry/biological Small molecule detection,rapid component identification and other fields.However,as the increase of the demand for substance detection,how to further improve the sensing performance of surface plasmon resonance sensing detection technology has become a research hotspot in the field of nanophotonics.At present,the structures that excite surface plasmons are mainly divided into two categories in the sensing system:one is the thin-film structure that produces surface plasmon polaritons,the other is the subwavelength microstructure that generates localized surface plasmons polaritons.Based on these two structures,this paper will study the generation of surface plasmons and their sensing performance.The specific research work is as follows:First,simulation and experimental research on the inducing of surface plasmons polaritons and it's sensing properties were carried out in thin-film.Based on angle type prism coupling to excite the surface plasmons polaritons,we simulated the influence of different silver film thickness and anti-oxidation film thickness on the resonance peak using FDTD.Through the analysis of the simulation results,the best structural parameters of the sensor chip were obtained,and the sensing sensitivity under the structural parameters was 107.2°/RIU.Then we designed and built a sensing experiment system based on surface plasmon resonance,and verified and analyzed the sensing sensitivity of the system using the sensor chip obtained by simulation.By measuring the sodium chloride solution with known refractive index,the sensitivity of the three experimental results were 86.71°/RIU,88.26°/RIU and 92.83°/RIU respectively.Finally,the reasons for the difference in sensitivity were analyzed.Secondly,the production and sensing performance of microstructure surface plasmons Polaritons were simulated and analyzed.Based on the wavelength-type prism coupling to excite surface plasmons polaritons,the sensing performance of three microstructures was simulated and analyzed.The effects of different structural parameters of the nano-ring microporous structure,asymmetric dimer microporous structure,and symmetrically broken nano-disc structure on the surface plasmon resonance peak were discussed in detail.According to the peak shape of the resonance peaks of different structures,the Fano resonance phenomenon of the microporous structure was more obvious than that of the disc structure.Therefore,the first-order and second-order resonance peaks of the microporous structure were simulated and analyzed,while for the disc structure,only the first-order resonance peaks were analyzed.The best structural parameters were obtained through the analysis of₀(66))?₀(66))and the half-width of the resonant peak under different structural parameters.Under this structural parameter,the three structural sensing characteristics were simulated and studied respectively.Finally,the sensitivities of the two-level resonant peaks of the nano-ring microporous structure were 211.11nm/RIU and 359.4 nm/RIU,and the sensitivity of the two-level resonant peaks of the asymmetric dimer microporous structure were 210 nm/RIU and 145.89 nm/RIU,respectively,The sensitivity of the first-order resonance peak of the symmetrically broken nanodisk structure was 265 nm/RIU.The research results have important reference value for the design of higher sensing performance microstructures.