An exact method for simulating boundary conditions for mesh termination in finite‐difference techniques

Finite‐difference methods are standard techniques for solving the differential form of Maxwell's equations. In spite of many advantages, a drawback of the technique is how to implement an absorbing boundary condition in an essentially exact fashion. In this article an absorbing boundary condition is proposed based on the Green's functions arising in integral equations. The radiation condition in this approach is built up iteratively as the solution progresses, utilizing the Green's function. In the proposed method only two layers of meshes outside the boundary may be sufficient. Examples have been presented for the electrostatic case to illustrate the accuracy and convergence of this new technique. © 1995 John Wiley & Sons. Inc.