Simulation of longitudinally magnetized three-dimensional magneto-optical devices by a full-vectorial beam propagation method

A full three-dimensional vector finite-difference beam propagation method is developed and tested. In this scheme, a delicate way to discretize the coupled equations is incorporated. The resulting matrix for the difference equation then has a tri-diagonal structure, which makes the program robust and, computationally, efficient. The transparent boundary condition is also improved so that any exponential growth at a boundary is suppressed. The method is applied to the simulation of magneto-optical devices and the design of a waveguide-based optical switch, with −25 dB isolation, is presented.