Study On The Mode Coupling And The Properties Of Light-controlled In Graphene/dielectric Multilayer Structure

In view of the unique optical and electrical properties of graphene,the study of light-controlled properties of graphene-based composite micro-nanostructures is becoming an important research field in nano-photonics.The excitation coupling of the plasmons in the graphene/dielectric composite structure and the controllable optical properties of the structure have attracted much attention.In this paper,the mode distribution and dispersion properties of the graphene/dielectric/graphene multilayers are studied.For TM polarization,the mode distribution and dispersion relation were obtained by numerically solving the Maxwell equations.In addition,the influence of dual nonlinearity on dispersion relation is discussed,and we find that the graphene's nonlinearity affects strongly the dispersion properties compares to the dielectric's nonlinearity.The sine grating modulation is introduced into the graphene/dielectric/ graphene multilayer structure.The high Q-factor and optical switching properties of the structure are studied.For the graphene/dielectric/graphene nanostructures,the TM wave vertical incidence is considered,we give the transmission and absorption spectra of the structure.It is found that the graphene plasmonics can be excited.And then the influence of structural parameters on the Q-factor was studied.Based on the special transmission properties,we designed a multi-wavelength alloptical switching device.The modulation depth of the device is up to 99%.Based on the properties of high Q-factor of graphene/dielectric/graphene multilayer structure,the sensing medium was introduced and the sensing properties of the structure were studied.Since the smaller chemical potential corresponds to the narrower formant,the smaller chemical potential is chosen,and the sensing properties of the structure are given respectively.It is found that under the deep grating modulation,the structural sensitivity S is up to 2617 nm/RIU refractive index unit),and the FOM is up to 764 RIU-1.Under light grating modulation,the ultra-high FOM can be achieved.The numerical results of FOM is 1495 RIU-1.