| The integrated optical path is composed of tiny photonic devices.However,since the size of the photonic device is limited by the diffraction limit,it is difficult to nanometerize and integrate it.By using surface plasmons,the diffraction limit can be broken,and the photonic device can be nanometerized and integrated.Graphene,as a two-dimensional material with special electrical and optical properties,has flexible tunability,strong field confinement capability,and lower transmission loss compared to traditional metal surface plasmons.Hexagonal boron nitride is a natural twodimensional material with hyperbolic dispersion characteristics.Because the hyperbolic phonon polarization mode supported by it has a dispersion curve similar to that of plasmons on the surface of graphene,graphene-hexagonal nitrogen Boron heterojunctions have many superior properties.When light is guided through the waveguide,the loss of light by graphene and hexagonal boron nitride eventually turns into heat.At present,most of the research work has focused on the optical properties of graphene surface plasmons or graphene-hexagonal boron nitride heterojunctions,but the research on their photothermal properties has been limited and needs to be further explored.In addition to optical feature size,thermal feature size is another important factor that limits the maximum integration density of optical interconnects,which should be minimized in actual design.Therefore,accurate characterization of photothermal characteristics is essential for the design and optimization of these structures.This paper focuses on the photothermal effects of graphene plasmon waveguides,applies finite element numerical methods to the calculation of light and thermal fields,and realizes the multiphysics integration simulation and analysis of surface plasmon waveguide devices.Firstly,how to establish the finite element boundary value problem of the light field based on the electric field vector wave equation and electromagnetic boundary conditions is introduced.According to the ritz variational method and Galerkin weighted margin method to establish a light field finite element matrix equation,by solving matrix equation for the electric field distribution can be obtained.Then,using the heat generated by the electric field as a heat source,the boundary value problem of the thermal field part is established based on the heat conduction equation and thermal boundary conditions,to solve the temperature distribution can be obtained.Then,based on the finite element numerical framework,the photothermal effects of two novel hybrid graphene surface plasmon waveguides were modeled and characterized.The graphene sheet is equivalent to a two-dimensional impedance surface,which effectively reduces the calculation amount of traditional three-dimensional modeling.The main factors affecting the photothermal performance of these two waveguide structures are analyzed,including the conductivity of graphene,the wavelength of incident light,and Power density.These findings reveal their physical properties from a photothermal rather than an unconventional optical perspective,and suggest that the thermal characteristic size is the underlying factor affecting the maximum integration density,providing useful insights into the design and use of hybrid graphene surface isobaron waveguides in optical interconnections.Finally,a graphene-coated hexagonal boron nitride nanowire waveguide structure is analyzed,which can support the surface plasmon-phonon polarization hybrid mode.Based on the finite element method and the effective refractive index method,the mode analysis of the surface plasmon-phonon polarization mixed mode supported by this waveguide was performed.The temperature was calculated based on the electric field combined with the material loss as the heat source.According to the changes,the performance of graphene-coated hexagonal boron nitride nanowire waveguides is analyzed from multiple angles,which provides a meaningful reference for practical design. |
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