使用有限元方法（FEM）分析了椭圆柱形金属线在0.5 THz太赫兹波下的表面等离激元的特性。这种场与圆柱形金属线表面等离激元类似，具有低损耗、低色散的特性。研究结果表明，随着长轴与短轴比值的增加，椭圆柱形金属线的场逐渐分裂开并越来越向椭圆的两个尖端区域集中，损耗也一直在显著减小，故传播距离始终在增大。由于这些特性，椭圆形横截面金属线适用于太赫兹波导、聚焦以及成像等领域。

Using the finite element method (FEM), we analyze the characteristics of the surface plasmon polaritons of an elliptic cylinder metal wire at 0.5 THz. The field has properties of low absorption and low dispersion, which is similar to that of a cylindrical metal wire. The results show that, as the major-to-minor semi-axis ratio of the elliptic cylinder metal wire increases, the fields are gradually separated and concentrated to its tip regions, while the absorption keeps notably reducing, so the propagation length continually increases. Because of these properties, elliptic cylinder metal wire is appropriate for applications such as terahertz waveguide, focusing, and imaging, etc.