An unsplit-field higher order nearly perfectly matched layer (NPML) based on the auxiliary differential equation approach is introduced in three-dimensional finite-difference timedomain lattices. The proposed scheme has the advantage of both the NPML scheme and the higher order concept in terms of the improved absorbing performance and considerable computational efficiency. By incorporating with the generalized material independent concept, the proposed implementation is independent of the material's type. Thus, it has the advantages of terminating arbitrary media without changing the updated equations in the PML regions. Its effectiveness and efficiency is further demonstrated through numerical examples.

中文翻译：

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EM模拟中任意介质的非分裂场高阶近PML

在三维有限差分时域格中引入了基于辅助微分方程方法的非分裂场高阶近乎完美匹配层（NPML）。所提出的方案在改进的吸收性能和可观的计算效率方面具有NPML方案和高阶概念的优点。通过结合广义的材料独立概念，建议的实现方式与材料的类型无关。因此，具有在不改变PML区域中更新的方程式的情况下终止任意介质的优点。通过数值示例进一步证明了其有效性和效率。