Fano Resonances Of Panda-eye-like Nanostructures And Tunable Filters With Inverted T-structure Waveguides With Defects

Surface plasmon photonics is a new subject which applies surface plasmon technology to the field of photonics.It is the most important part of nanophotonics.Due to the novel effects and interesting physical mechanisms of surface plasmons,especially the optical properties produced by the surface plasmon resonance of precious metals have great potential and value in practical applications,so it has attracted much attention in recent years.With the rapid development of modern information technology,the demand for miniaturization and high integration of devices is higher and higher.People begin to design optical devices based on local surface plasmon and propagation surface plasmon,such as surface plasmon elements and circuits,nano waveguides,surface plasmon photonic chips,couplers,modulators,switches,sub wavelength devices Optical data storage and super-resolution imaging beyond diffraction limit realize the transmission and processing of optical information in nano-scale.According to the development background and current situation of surface plasmon and the previous research results in this field,this paper mainly does two parts of research.In the first part,the Fano resonance and its physical effects of panda's eye-like dimer nanostructure is designed and studied.In the second part,two kinds of coupling systems based on metal-dielectric-metal waveguide structures are designed and studied,and the optical properties and physical effects of the two systems are studied respectively.The first part of the research is based on local surface plasmons.The designed structure of the panda's eye-like silver nano-dimer can generate high-order magnetic modes and achieve multiple Fano resonances.The intensities of the magnetic modes can be effectively and independently controlled by changing the nano-structure parameters.In addition,the electric field and magnetic field can reach 390 times and 38 times of the incident field by changing the nano-structure parameter,respectively.This structure has potential applications in multi-band surface-enhanced spectroscopy and biochemical sensing.The second part is based on propagation surface plasmons.In this part,two kinds of waveguide structures based on metal-dielectric-metal are designed and studied.The first structure is a basic system that can implement the filtering effect.The filter band can be widened and moved by changing the structure parameters.In order to improve the performance of the system,a second structure is designed,which is actually an optimization of the first system.Due to the coupling between the continuous state and the discrete state,Fano resonance,electromagnetic induced transparency and filtering bands appear in the transmission spectrum.The results show that Fano resonance and electromagnetic induced transparency can be regulated independently or simultaneously by changing the structural parameters.The waveguide coupling systems can dynamically control the light,which is beneficial to the applications of slow light and filtering,and has good filtering performance.