Study On Optical Signal Control Method And Plasma Characteristics Of Micro-nano Sensor

Surface plasmon can break through the main limitation of traditional optical device miniaturization-diffraction limit.The integration and miniaturization of components also promote the research of surface plasmon.Its unique optical characteristics open the door for researchers to optical communication and quantum information.The local surface plasmon resonance of nanoparticles is a unique optical property of micro nano sensor detection methods.The study of plasma properties of noble metal nanostructures can be widely used in various research fields,such as biochemical sensors,optical information storage and nano photonics.The causes of attention are the flexible control of spectral response and the enhancement of nano particle film junction strong local field.The silver nanorods have the highest sensitivity to environmental changes.In Chapter3,the surface plasma extinction cross section and electric field distribution in the silver nanorod-gold film nanostructure are numerically simulated.It is found that the larger the aspect ratio of nanorods is,the more sensitive the nanostructure is to the change of the surrounding medium.The relationship between the two is linear,which can be used to detect the concentration/refractive index of the surrounding gas or liquid environment by the micro-nano sensor.Combining the sensitivity and FWHM(full width at half maximum),the nanostructure system with the highest quality factor was obtained,and the gap material PE was added into the nanostructure system.The effect of gap distance on the local field intensity and resonance wavelength showed an exponential decreasing trend.This study can be used for the development of medical diagnostic equipment with high sensitivity for the detection of biological molecules.Finally,in order to better analyze the plasma mode of silver nanorod-gold film nanostructure,the plasma hybrid mode of nanorod monomer/dimer-gold film structure is analyzed by changing the incident angle and electric field direction.Compared with nanoparticles with core-shell double-layer metal structure,the instability of pure silver nanorods in the air limits their application fields.However,The core-shell nanorods not only have the physicochemical properties of core-shell metal nanostructures,but also have potential function enhancement due to the synergistic effect between different metal material combinations.In Chapter4,the relationship between the electric field intensity and resonant wavelength of the gold-core-silver-shell nanorods and the volume ratio of silver on the outer surface is explored.With the increase of the silver volume ratio,the extinction cross section strength of the gold core-silver shell nanorods/gold film increases obviously,and the resonance peak shows blue shift and FWHM narrows.The optical signal can be regulated by adjusting the nanostructure.