Tunable Sinusoidal Structure Graphene Surface Plasmon Resonance Sensor

Surface Plasmon Resonance(SPR)describes an optical phenomenon when a light source is used to illuminate a metal surface,the photons and the self-electrons present on the metal will interact along its surface under certain conditions to produce a dense oscillation.This effect generally occurs at the boundary of the metal thin film.However,the electromagnetic properties of traditional metals are difficult to change,and it is difficult to control plasmons.Compared with conventional precious metals,graphene has the advantages of lower optical loss,stronger binding and dynamic adjustability.Therefore,related research on graphene surface plasmon resonance sensors has become a hot topic in recent years.By using graphene as the detection layer,the sensitivity of the SPR sensor can be greatly improved.However,problems such as edge effects in graphene and the narrow range of SPR that can be tuned limit its use in optical and optoelectronic applications,and graphene materials are structurally fixed in such modes,resulting in its resonance wavelength being stable.Although recent researchers have discovered that the mechanical wrinkling of graphene can be used to generate different surface structures while maintaining reversibility in operation,no one has yet explored the application of this wrinkled graphene structure to a reconfigurable SPR sensor.In the research of this paper,first of all,based on the excellent optical properties of graphene,it is used as the SPR excitation material instead of metal.A SPR sensor using continuous pleated structure graphene film for strong plasmon resonance sensing is proposed.Through computer simulation,the randomly distributed folds on the grating film and design it into a standard sinusoidal structure to realize optical sensing,and use the wavelength detection method to acquire the performance of the sensor in real time.Then analyze the influence of different parameters of the sinusoidal graphene film on the sensor spectrum including chemical potential,thickness,duty cycle,etc.By adjusting the parameters of the sinusoidal fold,broadband tunability can be achieved,and the wavelength range of the SPR excited by the graphene sensor is increased.According to the reasonable configuration of the sensor parameters,the optimal sensitivity of the sensor is calculated.Then add a flexible substrate under the graphene film,analyze the effect of the addition of the substrate on the resonance wavelength,and use the elastic properties of the substrate to perform tensile and compression deformation operations on the application of lateral force,ensure that the overall is within the effective elastic range maintain reversibility.At this time,the substrate will drive the surface structure to cause the spectrum excited by the graphene film mounted on it to change the position corresponding to the resonant wavelength,which is modulated.Controlling the degree of film deformation can realize the precise modulation of the resonance wavelength generation position,and finally design the corresponding wavelength modifiable SPR sensor.