Study On Plasmon-induced Effect Based On MIM Structure

With the development of optical information technology,the high integration,ultra-fast nonlinear response and miniaturization of structure of photonic devices have become the inevitable trend and pursuit of future optical research and development.However,in the field of photonics,the existence of diffraction limit restricts the development of photon integration.Surface plasmon polaritions(SPPs)is a special electromagnetic wave generated by the interaction between light and free electrons on metal surface.Due to its characteristics of low dimension,strong transmission and subwavelength,it is possible to realize integrated nano optical elements,and has become one of the research hot spots of modern nano optics.Among many waveguide structures based on surface plasmon,the metal-dielectric-metal(MIM)waveguide has attracted more attention due to its advantages of compact structure and high integration.In recent years,plasmon-induced effect based on MIM,which includes plasmon-induced transparency(PIT)and plasmon-induced reflection(PIR),has shown the potential application value in the field of micro-optics because of its low loss,strong dispersion and narrow band width characteristics.In this paper,two kinds of coupling structures of the plasmon-induced effect based on MIM waveguide(hexagonal square ring resonator and the double side coupling square cavity with embedded rotating structure)are proposed,and their transmission characteristics are studied and analyzed,showing their application prospects in nano sensors,optical switches and other photonic devices.The specific research contents of this paper are as follows: 1.A coupling structure of hexagonal square ring resonator based on MIM waveguide is proposed.The transmission characteristics of the structure are studied by using the finite element method(FEM),and the mode field distribution and transmission spectrum are analyzed in detail.The results show that the coupling structure of the hexagonal square ring resonator can produce plasmon-induced reflection(PIR),and the dynamic tuning of transmission spectrum can be realized by adjusting the geometrical structure parameters of the system.The comparative study shows that this structure exhibits good sensing and fast/slow light characteristics(800 nm/RIU sensitivity and-0.54 ps group delay)in a small range of structure size,and the transmission characteristics are less affected by machining errors.Furthermore,the double PIR and ultra-narrow PIT effect are achieved by adding a hexagonal square ring waveguide structure of the same size.2.A two-sided square cavity coupling structure with embedded rotating rectangular core was designed and studied.The simulation results show that the system produces obvious PIT effect at multiple wavebands under the rotation of the rectangular inner core,and the dynamic tuning of the transmission window can be realized with different rotation angles of the embedded structure.The transmission curves can be dynamically tuned by changing the geometric parameters of the square cavity and the embedded structure.At the same time,when the structure size and rotation angle are appropriate,the single PIT effect can be realized in different wavebands.