This article applies a new method to analyze modes in empty waveguides having perfectly conducting walls and a rather generic cross‐section. The method is based on a coordinate transformation that maps the generic profile of the waveguide cross‐section to a circular waveguide (CW) filled with an anisotropic material. Modes in this latter waveguide can be represented as a series over the corresponding free‐space CW modes. This representation is particularly useful if used as a modal expansion over the port of a 2.5D or 3D device treated with a transformation optics approach. The method is particularly efficient when the waveguide is “similar” to a CW. Applications are shown to the analysis of some waveguides of arbitrary cross‐section with a view on practical applications.

中文翻译：

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通过变换光学方法计算任意形状波导中的模式

本文采用一种新方法来分析具有完美导电壁和相当普通横截面的空波导中的模式。该方法基于坐标变换，该坐标变换将波导横截面的一般轮廓映射到填充了各向异性材料的圆形波导（CW）。后一个波导中的模式可以表示为对应的自由空间CW模式上的一系列。如果用作通过转换光学方法处理的2.5D或3D设备端口上的模式扩展，则此表示特别有用。当波导“类似于” CW时，该方法特别有效。结合实际应用，将其应用于分析任意横截面的某些波导。