The finite-di ffrence time-domain(FDTD) method is applied to solve the Dirac-like equation of a graphene sheet. A virtual absorbing layer (VAL) is proposed to achieve low reflection of wave function at the boundary of a graphene sheet. Empirical parameters are tuned to optimize the performance of the VAL. The Klein tunneling effects on a graphene sheet are simulated to confirm the effectiveness of this FDTD scheme and the VAL.
