A Loss-Controllable Absorbing Boundary Condition for Surface Plasmon Polaritons Propagating Onto Graphene

The development of a robust terminating boundary scheme for the transverse magnetic surface plasmon polaritons, supported on graphene, is introduced in this paper and incorporated in the finite-difference time-domain (FDTD) method. First, the 2-D FDTD algorithm is adjusted to efficiently model the graphene sheet as a surface conductivity, and the effect of the scattering rate-the main loss mechanism of graphene-on the surface wave propagation properties, is thoroughly studied. Then, the new scheme is optimally formulated via the prior scattering rate and combined with the FDTD algorithm. Its enhanced performance is successfully validated for several 2-D setups and a 3-D configuration with a surface wave traveling on a graphene microribbon waveguide.