Abstract
A combination of a higher order accurate FDTD algorithm, a decoupling procedure, and a moving computational window is presented for the solution of the phase-sensitive second harmonic generation problem. The requirement that the spatial step size in the propagation direction be a small fraction of the wavelength is significantly relaxed using the proposed efficient FDTD schemes. It has been shown that these fully explicit schemes deliver convergence of the solution using significantly less computation time and less memory requirement as compared to the standard FDTD scheme.