Radiation Modes and Roughness Loss in High Index-Contrast Waveguides
Radiation Modes and Roughness Loss in High Index-Contrast Waveguides
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DOI：
10.1109/jstqe.2006.881648
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发表时间：
2006-11
影响因子：
4.9
通讯作者：
C. Poulton;C. Koos;M. Fujii;A. Pfrang;T. Schimmel;Jürg Leuthold;W. Freude
中科院分区：
文献类型：
--
作者：
C. Poulton;C. Koos;M. Fujii;A. Pfrang;T. Schimmel;Jürg Leuthold;W. Freude
我们使用耦合模式理论经典方法的新变体来预测矩形高折射率对比度波导中的散射损耗。该三维 (3-D) 模型预测的损失远大于使用以前的处理方法计算的损失，这些处理方法用二维对应模型近似真实的 3-D 辐射模式。理想波导的 3-D 辐射模式以一系列柱面谐波展开，并计算由于侧壁扰动导致的引导模式和辐射模式之间的耦合。然后可以半解析地计算波导衰减。研究发现，主要的损耗机制是辐射而不是反射，并且横向电极化表现出比横向磁极化大得多的衰减。该方法还给出了可用于低损耗光波导设计的简单规则。使用原子力显微镜测量了 InGaAs/InP 基座波导的侧壁粗糙度的结构特性，发现测量的衰减与模型预测的衰减非常吻合
We predict the scattering loss in rectangular high index-contrast waveguides, using a new variation of the classical approach of coupled-mode theory. The loss predicted by this three-dimensional (3-D) model is considerably larger than that calculated using previous treatments that approximate the true 3-D radiation modes with their two-dimensional counterparts. The 3-D radiation modes of the ideal waveguide are expanded in a series of cylindrical harmonics, and the coupling between the guided and radiation modes due to the sidewall perturbation is computed. The waveguide attenuation can then be calculated semianalytically. It is found that the dominant loss mechanism is radiation rather than reflection, and that the transverse electric polarization exhibits much larger attenuation than transverse magnetic polarization. The method also gives simple rules that can be used in the design of low-loss optical waveguides. The structural properties of sidewall roughness of an InGaAs/InP pedestal waveguide are measured using atomic force microscopy, and the measured attenuation is found to compare well with that predicted by the model