Dispersion HIE-SF-FDTD Method for Simulating Graphene-Based Absorber

This paper presents a novel dispersion hybrid implicit explicit single-field finite-difference time-domain (HIE-SF-FDTD) method which can be effectively used to simulate the graphene-based absorber. The stability condition of the proposed method is relaxed from the spatial mesh sizes along one direction which makes it a robust tool to simulate structures having fine details in one Cartesian direction such as thin graphene sheet. By applying the Crank-Nicolson (CN) scheme only to the electric field and a new time-splitting scheme to the graphene current density, the proposed algorithm is developed. In this method, not alike most of the FDTD algorithms in which both electric and magnetic fields are updated, only the electric field needs to be solved in each iteration. Thanks to the few and simple updating equations of the proposed algorithm, higher computational efficiency in terms of runtime is achieved. The accuracy and computational efficiency of the proposed method are demonstrated through comparison of the results obtained from the methods available in the literature.