Learning Forum

[Greg Baethge]

There are two approaches to define the optical properties of graphene in Lumerical’s optical solvers (FDTD and MODE):

1. Using a 2d surface conductivity model: This is the recommended approach since it is computationally efficient and has physical meaning given the atomic thickness of graphene. Most of the examples in the Knowledge Base use this approach. Graphene is included in the simulation as a 2D rectangle and its surface conductivity is given by the Kubo formula, which depends on three parameters: scattering rate, chemical potential and temperature. These parameters can be set in the material properties when creating the desired graphene material.   
2. Volumetric permittivity approach: Instead of a 2D rectangle we use a regular rectangle (with some thickness) and define the permittivity or refractive index. These are bulk properties but they can be related to the surface conductivity using: