A three-dimensional fourth-order finite-difference time-domain scheme using a symplectic integrator propagator

A new explicit fourth-order finite-difference time-domain (FDTD) scheme for three-dimensional electromagnetic-field simulation is proposed in this pap er. A symplectic integrator propagator, which is also known as a decomposit ion of the exponential operator or a general propagation technique, is dire ctly applied to Maxwell's equations in the scheme. The scheme is nondissipa tive and saves memory. The Courant stability limit of the scheme is 30% lar ger than that of the standard FDTD method. The perfectly matched layer abso rbing boundary condition is applicable to the scheme. A specific eigenmode of a waveguide is successfully excited in the scheme. Stable and accurate p erformance is demonstrated by numerical examples.