Research On Resonant Excitation Of Graphene Plasmon And Its Applications

In recent years,with the rapid development of advanced optical technology,the demand for semiconductor devices has gradually shifted in the direction of ultra-microscopicity and intensification.However,traditional silicon-based electronic chips are approaching their limits in terms of size and performance,which severely limits the development of semiconductor devices.Graphene plasmons processed strong optical field confinement,low intrinsic loss and real-time tuning in the sub-wavelength range,have made it possible for photons to replace electrons as information carriers and lead the booming development of integrated photonics.In this thesis,the simulation methods(time-domain finite difference method and finite element method)and theory methods(coupled mode theory,transmission matrix theory,and rigorous coupled wave theory)are used to investigate the optical properties and resonant excitation mechanism of graphene plasmons.Therefore,through cleverly designed micro-nano structures,graphene can be targeted and selectively realised in absorption,sensing,slow light and electro-optical modulation.The contents of this dissertation mainly include the following aspects:1)The resonance and excitation of the graphene plasmons(GPs)with different orders is analyzed and proposed using a hybrid grating graphene nanoribbons all-dielectric system.The excitation of high-quality resonance effects in the mid-infrared band is achieved by adjusting the substrate thickness that enables the generation of quasi-optical dark states.In addition,the dependence of the excitation of the GPs modes with multi-order on the structure period and Fermi energy is systematically investigated.It is verified that the resonance position of the GPs modes is proportional to the structure period and inversely proportional to the Fermi energy.In addition,it is demonstrated that a multi-band high-Q optical mode based on GPs modes can be achieved by adjusting the geometrical parameters and the angle of light incidence.This provides new ideas and approaches for the design of multi-band,high-performance absorbers.2)Considering that single-mode resonance cannot meet the practical operational requirements of optical devices,a simple and easy-to-implement graphene stack structure is designed to realize the multi-mode resonance and excitation of graphene plasmon polaritons.Time-domain finite difference method is used to analyze the spectral response of the structure,and the results show that the interference between four radiation modes can cause a 3PIT effect.These phenomena are analyzed by introducing a universal law called multi-mode resonance CMT coupling theory that contains the mode coupling amplitude and the correspond transmittance.It is demonstrated that the excited graphene plasmon polaritons permits the control through both Fermi energy level and carrier mobility of graphene.Finally,the properties of graphene stacked structures for terahertz-band plasma sensors are explored.This stretches the versatile application of multi-band sensors.3)Based on the metal-like properties of graphene,a graphene-Tamm hybrid system is proposed to achieve different optical resonant modes based on graphene,of which the field concentrations are within the graphene nanoribbons(graphene plasmon polaritons)and graphene sheet(graphene Tamm plasmon polaritons).The absorption spectral response of the system has been calculated using rigorous coupled wave theory,and the calculated values agree with the simulated values.The coupled oscillator model is used to describe the hybridization process of different optical modes.It is demonstrated that flexible manipulation of the hybrid optical modes is achieved by varying the geometrical parameters of the structure,the Fermi energy level of the graphene material,and the angle of light incidence.Furthermore,the system has a good slow-light response,which offers a new paradigm for tunable light-graphene interaction.4)Based on the above studies,the resonant excitation of graphene plasmon polaritons mode with other optical modes is investigated.A graphene-metal lossy system is constructed,exhibiting the strong coupling between guided-mode resonance and graphene plasmon polaritons resonance.The hybridization coupling properties and resonant transport properties between the two optical modes are investigated by finite element methods and RCWA method.By introducing an incident angle that can break the symmetry of the system,the BIC evolves into an observable quasi-BIC with a high-quality resonant mode.The resonance characteristics of the BIC are revealed by describing the relationship between the quasi-BIC resonance states and the Q factor.Based on the resonance characteristics of the guided-mode resonance and graphene plasmon polaritons,a numerical calculation method for the energy band structure and Q factor of the lossy system is constructed,and its calculation results are in good agreement with the simulation results.Finally,by varying the carrier mobility of the graphene,a switching modulation can be achieved.This contributes to various plasmonic device designs of graphene.