Numerical Study Of EIT-like And Slow Light Effects In MIM Waveguide With Rectangular Cavity

Surface plasmon polaritons(SPPs)are transmission behaviors of electromagnetic waves that are confined to the metal-dielectric surface and oscillate freely around the metal surface.An important feature of surface plasmon waves is the ability to break the diffraction limit of light at the nanometer scale.This important feature enables the control of light waves at the nanometer scale and is extremely important for the integration and miniaturization of optics.Metal-Insulator-Metal(MIM)plasma waveguide system has the simple structure,easy to manufacture,which attracted the attention of researchers.In this paper,three kinds of MIM surface plasmon waveguides are proposed,and the transmission properties and mode field distribution of surface plasmon waveguides are studied by COMSOL simulation software.In the analysis of MIM waveguide with rectangular cavity structure,due to the detuning between the two resonant cavities,the surface plasmon wave excited the transmission peak through the two resonant cavities,which results in the electromagnetic induced transparency phenomenon.By calculating the phase shift of the waveguide structure,the maximum delay of the waveguide structure is 0.28 ps,and the corresponding maximum group index is about 84.In the analysis of simple branched MIM waveguide structure,a double simple branch waveguide model is established.The influence of cavity length and intercavity distance on the electromagnetic induced transparency was analyzed.The optical delay under this structure was analyzed.The maximum delay was 0.098 ps and the maximum group index was 29.4.The results show that the rectangle tooth has influence on the transmission spectrum at the branch waveguide.When the rectangle tooth is located at the strongest magnetic field,the resonance wavelength is red shifted.When the rectangular tooth is located at the strongest electric field Department,the resonant wavelength blue shift.Using this feature to produce electromagnetic induction of transparent phenomena,the maximum delay of 0.049 ps.The maximum group index of this structure is 14.7.The results of this paper provide a reference for the integration of nanodevices.