Nonlinearity analysis of 2D materials by using GS-FDTD method

We present a new numerical method to study the linear and nonlinear response of dispersive and nonlinear 2D materials by incorporating a nonlinear generalized source (GS) into the finite-difference time-domain (FDTD) method. This new method is particularly powerful when applied to the analysis of 2D materials, as most such materials cannot be studied directly by traditional FDTD method due to their vanishingly small thickness. A typical graphene grating has been studied to verify the accuracy of the proposed GS-FDTD method, and its predictions agree well with other well-known frequency-domain numerical methods.