Research On Sensing Characteristics Of Surface Plasmon Resonance Based On MIM Structure In Micro-Opto-Electro-Mechanical Systems

Micro-Opto-Electro-Mechanical Systems(MOEMS)is a new type of micro-optical system produced by the combination of micro-optics,micro-electronics and micro-mechanics.Compared with traditional optoelectronic devices,the new micro-opto-electromechanical system can work normally under strong electromagnetic interference and strong corrosion,and has a wide range of applications in military,automation,biomedical and other fields.In the new micro-optic electromechanical system,Fano Resonance technology has become a hot spot in the field of MOEMS due to its unique performance.The main research contents of this paper are as follows:(1)We described the optical transmission properties of a surface plasmon polariton waveguide structure consisting of a metal-insulator-metal(MIM)waveguide and a semicircular resonant cavity coupled with a key-shaped resonant cavity.Finite element algorithm simulated the optical response of a MIM waveguide structure.The influence of the size of the resonant cavity structure on the Fano resonance line was investigated.Results demonstrate that variation of the key-shaped cavity asymmetry leads to the appearance of dual Fano resonances.When materials with different refractive index fill in the key-shaped cavity,the MIM waveguide structure achieves a sensitivity of 900/1350nm/RIU.This performance allows the waveguide to be used for nanoscale biosensor applications.(2)we designed a metal-insulator-metal(MIM)waveguide structure that consists of a branched semi-closed T-shaped waveguide coupled to an open square ring resonator.The finite element algorithm was used to numerically simulate the transmission characteristics and electromagnetic field distribution characteristics of the designed structure.We numerically analyzed the effects of changing the size of the branch,the coupling distance,and the opening size of the open square ring cavity on the Fano resonance spectrum.Increasing the refractive index of the filling medium in the open square ring resonator and the branched T-shaped waveguide results in an approximately linear shift in the resonance wavelength.In addition,the proposed MIM waveguide structure can be used to develop nanoscale biosensors with high sensitivity(S),figure of merit(FOM)values,and Q factors of 900/1300 nm/RIU,16.67/29.55,and 22.85/39.38,respectively.This structure was then applied to glucose concentration evaluations,and we found that changes in the glucose level resulted in a redshift in the Fano resonance spectrum.These experiments also revealed that glucose concentration can be quickly and easily calculated from the change in Fano resonance wavelength.These characteristics provide a solid foundation for the application of these novel MIM structures in the field of micro nano sensing.The surface plasmon waveguide structure studied above has the advantages of good sensing performance,simple structure,and high sensitivity.It has certain practical significance in the field of Surface Plasmon Resonance(SPR)sensing.