关于完全匹配层吸收边界条件中差分格式的讨论

对完全匹配层(PML)中Maxwell方程差分格式的推导，本文认为文献[1]求解微分方程时有不妥之处，给出了改正。根据PML介质中电磁波传播特性，我们还用直接方法导出差分格式的不同形式，在证明两者一致的同时指出后者更具精确性，并易于编程实现。最后利用实例验证了两种差分格式的吸收效果是等效的。

A Discussion on Difference Formulation in PML Absorption Boundary Condition

The errors for getting difference formulation from Maxwell equations in PML in [1] are indicated, and the correct derivation process through solving differen tial equation approach is presented. A second method directly yields different d ifference formulation based on the propagation characteristic of waves in PML me dium. The two different difference formulations are proved to be consistent. How ever, the latter is more accurate and easy to implement. Finally, a simple numer ical example validates that the absorbing performance is identical from the two difference formulations.