A Novel Absorbing Boundary Condition for the 3-D Split-Step FDTD Method

In this letter, a novel absorbing boundary condition (ABC) is proposed for the 3-D split-step finite-difference time-domain (FDTD) method. Compared with the traditional Mur first-order ABC, the proposed ABC is simpler and requires less additional computation. Numerical simulation results show that the reflection error of the proposed ABC is much lower than that of the traditional Mur first-order ABC and its modifications. Further investigation shows that the accuracy of the proposed ABC is almost equivalent to the Mur second-order ABC.