The Study Of The Field Enhancement And Fano Resonance Of Au Nano-structure

In recent years,as the development of computer technology and nano processing technology,and the raise of the surface plasmonics,a variety of new features have been presented about the interaction of metal nanostructures and light,such as near-field electromagnetic enhancement,surface electromagnetic confinement,Fano resonance,negative refraction and so on.This paper had further study on the sensing signal properties of nano-structures based on surface plasmonics optic,first designed coupled V-structured nano-antenna for electromagnetic field enhancement that can be utilized in enhancing the detecting signal of Raman spectroscopy,then designed the splitting rectangular golden nanostructures and researched its unified attenuation characteristics of mixed polarization angle and environment sensing characteristic,finally studied a symmetrical triangle golden nanostructures and explored the application of the structure in the aspect of angle sensor.The research contents and innovative work consist of the following three parts:1.A symmetrical V-structured nano-antenna was designed.We studied the effects of structural parameters on the charge distribution and analyzed the electric field enhancement factor in the central region of the nano-antenna.Then we used structural coupling methods to strengthen electromagnetic field intensity in the central region.Our results demonstrated that the charge distribution of the nano-antenna could be controlled by regulating the structural parameters,leading to the change of electromagnetic field intensity.In addition,electric field enhancement was achieved by coupling of multiple V structures.The multiple V structure could be used in surface-enhanced Raman scattering due to the electric field enhancement in its central region,the way of multiple coupled structure has a guiding significance for further enhancing the electric filed.2.Nanorods polymer or splitting nanostructures can form obvious Fano resonances.We designed a split metal nano rectangular structure,and investigated the formation mechanism of the Fano resonance of the splitting metal nano-rectangle,the effects of structural parameters on Fano resonance peak,the change of the extinction spectra when the incident field in different polarization direction.The results show that Fano format has a very obvious move when ambient refractive index changing and the FoM can reach 11.8.The same intensity of extinction rate can be seen in the specific infrared wavelengths when the incident light goes through the splitting metal nano-rectangle in different polarization direction.The same extinction rate of laser intensity in different polarization direction has important application on forming uniform homogeneous attenuation for laser of mixed polarization angle.3.The symmetrical golden triangle was considered in this paper.We investigated the regulated effects of the structural parameters to Fano resonance peak,and the effects of the asymmetry to the Fano resonance peak.Then we investigated the changes of the Fano resonance varied with the triangle rotation angle.The results show that we can regulate the Fano resonance peak well by changing the structural parameters of the triangle,we can also get great Fano resonance spectroscope by setting fit structural parameters.The Fano resonance peak of the antenna has obvious changes when the rotation angel of the triangle varies from 0° to 5°,the sensitive feature of the antenna to angle extends its application in the angle sensor.