Design And Research Of Deep Subwavelength Components Based On MIM Waveguide

Surface Plasmon Polaritons(SPPs)is a phenomenon that a unique resonance occurs when light is incident at a Metal-Insulator(MI)interface at the same frequency and resonate with the free electrons at the metal surface.The electromagnetic field is confined in a small area and enhanced due to the energy of the optical field is bound at the surface of the MI interface,which allow SPPs to break the diffraction limit and is highly sensitive to metal type,dielectric environmental and nanoscale dimensions.As the vast majority of research has completed,SPPs based on Metal-Insulator-Metal(MIM)waveguides is now studied deeply by scholars worldwide due to their sub-wavelength scale,simple construction,easy integrate and high reliability.The desire to develop optical devices in its role as sensors,absorbers,filters,and optical switches realized by Lorentz resonance,Fano resonance,and plasmon induced transparency in MIM waveguide cavities has revived interest in SPPs.Here,each work is established on the MIM waveguide based on SPPs,combing construction of models,simulation calculations and theoretical analysis,to study the optical characteristics.The main research elements are as follows:(1)A Q-shaped resonant plasmonic system based on SPPs is designed as a refractive index sensor.The transmittance spectral with two resonant modes can be accessed using Finite Difference Time Domain(FDTD)method and analyses by Multimode Interferometric Coupled Mode Theory(MICMT),which shows a highly consistent.Meanwhile,the effect of the four structural parameters of the Q-shaped resonant cavity on the transmission spectrum is studied and the results showing that the two resonant modes can be independently tuned with weak dependence between sensitivity and parameters.According to the sensing index,the sensitivity of the device is 1578 nm/RIU and the figure of merit is 175.The results of the study effectively improve the sensitivity and figure of merit,which ensure the necessary performance of the structure as a sensor.(2)A plasma structure with an elliptical resonant cavity coupled to a stub MIM waveguide,simulated using Finite Element Method(FEM)and agreement with MICMT theory and standing wave resonance theory,is proposed as the refractive index sensor and slow light devices.The resonance modes are increased by adding symmetry breaking and side coupling while effectively increasing the sensitivity over the base structure.The optimal parameters are chosen to give a sensitivity of 1400 nm/RIU and a figure of merit of 189.6 while the slow-light parameters are calculated to give a delay time and group index of 0.128 ps and 19.21 respectively.(3)A plasma system based on a square-ring resonant cavity coupled with a stub waveguide is constructed and the formation of the Fano resonance is systematically explained by magnetic distribution and theory.With DAST electrooptic material is added in the square ring resonant cavity and the change of Fano resonance wavelength is controlled by using voltage so that it can be dynamically tuned after the device is processed.The structure can be used as a micro-voltage sensing considering the electrical control properties of the DAST material.