发表机构
School of Electrical Engineering, Korea Advanced Institute of Science and Technology（韩国科学技术院电气工程学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文利用仅四个相同波导的Su-Schrieffer-Heeger链的拓扑边缘态，实现了一种对长度和制造误差稳健的任意比例功率分配器，并通过理论和实验验证了其阶梯式功率传输特性。
AI 中文摘要
拓扑边缘态为光子器件和系统提供了一条稳健的路径，使其在存在结构缺陷时仍能保持功能。拓扑波导阵列已被证明能够提供稳健的耦合，但仅限于两个边缘波导之间的完全功率传输——实现任意中间比例的稳健方法此前仍属未知。在此，我们展示了由仅四个相同波导实现的有限Su-Schrieffer-Heeger链的拓扑边缘态，能够构成一个任意比例的功率分配器，其分配比例对器件长度和制造误差均具有稳健性。两个近简并的边缘超模拍频产生阶梯式功率传输，具有平坦、对长度不敏感的平台，这与传统定向耦合器的正弦传输形成对比。该平台上的分配比例由两个波导间隙之差决定，从而对相关的制造偏移免疫。我们从理论上推导了这一行为，并在常规绝缘体上硅平台上进行了数值和实验验证。除了该器件，我们的分析可应用于一般拓扑波导阵列，而这一稳健的分配器为制造容差光子电路提供了实用的构建模块。
英文摘要
Topological edge states offer a robust route to photonic devices and systems that remain functional despite structural imperfections. Topological waveguide arrays have been shown to deliver robust coupling, but only for full power transfer between the two edge waveguides---a robust route to an arbitrary intermediate ratio has remained unknown. Here we show that the topological edge states of a finite Su-Schrieffer-Heeger chain, realized with only four identical waveguides, form an arbitrary-ratio power splitter whose ratio is robust to both the device length and fabrication errors. Two near-degenerate edge supermodes beat to produce a step-like power transfer with a flat, length-insensitive plateau, in contrast to the sinusoidal transfer of a conventional directional coupler. The splitting ratio at this plateau is governed by the difference between the two waveguide gaps, making it immune to correlated fabrication offsets. We derive this behavior analytically and confirm it numerically and experimentally on a conventional silicon-on-insulator platform. Beyond this device, our analysis can be applied to general topological waveguide arrays, while the robust splitter offers a practical building block for fabrication-tolerant photonic circuits.
Comments13 pages, 4 main figures and 5 supplementary figures
