Research On Regulation And Blinking Suppression Application Of The Silver Surface Plasmon Polaritons

The surface plasmon polaritons of the noble metal can be used to achieve the optical propagation in the subwavelength area due to the breakthrough of the diffraction limit of the traditional beam, which has attracted wide attention in recent years. Among them, surface plasmon polaritons of silver nanowires have been characterized by small intrinsic loss. The surface plasmon polaritons of the silver nanowires had been used in the enhancement of Raman scattering, biological labeling and detection. However, the study of the surface plasmon of the Ag nanowires is in the primary stage in general,compared with the traditional electronic devices, the excitation of the surface plasmon polaritons is not stable, and the transmission loss is large, and it is not able to realize the application of photonic integrated devices at the current technology. Therefore, to realize the large-scale application of the surface plasmon polaritons, it also needs to do the intensive study.In this paper, the surface plasmon polaritons of silver nanowire are studied, being aimed at researching the regulation and applications of the silver surface plasmon polaritons.The main research contents and conclusions are as follows:(1) Studying several surface plasmon polaritons characteristics, energy confinement, hot energy site, propagation and coupling of silver nanowires upon the change of the surrounding dielectric environment. The results show that the uniformity of the field around the nanowire is dependent on the homogeneous feature of the surrounding dielectric environment. For a homogeneous dielectric environment, the properties of energy confinement and propagation length depend on the value of the refractive index of dielectric material. For an inhomogeneous dielectric environment,hot energy spots are brought and focused near the material with larger refractive index.The simulation results of two coupled nanowires demonstrate that both the distribution and the refractive index of the surrounding dielectric material affect the surface plasmon polaritons coupling distance.(2) A self-conducted laser-optical set-up is conducted to explore the influence mechanism of excitation degree of the surface plasmon polaritons on the coupling efficiency of the silver nanowires. Fiber optical taper was used to stimulated the surface plasmon polaritons in the near field. The degree between the fiber optical taper and the silver nanowire was changed by an R axial rotation. According to the experimental results, the coupling efficiency was effected by the intersection degree between the fiberoptical taper and the silver nanowire, and the value reached the peak when the angle was 0°, to the contrary, the value of coupling efficiency reached the minimum when the angle was 90°。(3) The self-conducted confocal microscopy system is used to study the blinking behavior of the quantum dots(CdSe/ZnS) deposited on the glass and two mutual parallel silver nanowires respectively and investigate the influencing mechanism of intermittency when the QDs coupling with the silver nanostructure. Evident blinking events were observed when the QDs were deposited on the glass and excited with a semiconductor laser continuously. However, distinct suppression appearance was discovered when the silver nanowires were added and the communal part of two mutual parallel silver nanowires had a more evident influence than the individual part. The coupling of the fluorescence and the surface plasmons derived from the silver nanowires is considered to be account for the phenomenon.