AI 中文总结
研究人员将g-TCMT模型扩展到n阶串联耦合MRR系统，验证其在n≤4时的有效性，探究n≥5时的局限性，并将其应用于非厄米光子学的PT对称结构。
AI 中文摘要
本文将我们先前开发的广义时域耦合模理论（g-TCMT）模型，从简单的双耦合微环谐振器（MRR）系统扩展到高阶n个串联耦合MRR系统。通过将每对相邻MRR视为单个“等效谐振器”，我们证明了对于n≤4的系统，g-TCMT与传输矩阵法（TMM）得到的数值结果在光谱谐振位置上具有极好的一致性。该方法的有效性取决于交换对称性是否存在，因此我们将这些结构称为具有交换对称性的耦合谐振器光波导（CROWe）。我们用n≥5的强耦合系统示例探究了该方法的局限性。最后，我们探究了此类高阶CROWe在非厄米光子学中的应用特性，即部分组成MRR存在增益、其余存在损耗，从而产生宇称-时间（PT）对称性。
英文摘要
In this paper, we extend our generalized Temporal Coupled Mode Theory (g-TCMT) model, developed earlier [1], from a simple, dual-coupled micro-ring resonator (MRR) system to higher-order, n-serially coupled MRRs. By treating each pair of adjacent MRRs as a single `equivalent resonator', we demonstrate excellent agreement in spectral resonance position, between the g-TCMT and numerical results obtained using the transfer matrix method (TMM), for systems up to and including order n=4. The validity of this approach hinges on the existence, or otherwise, of exchange symmetry, and so we refer to these structures as Coupled Resonator Optical Waveguides with exchange symmetry (CROWe's). We explore the limitations of our approach with illustrative examples of strongly coupled systems of order n \geq 5. Finally, we explore the properties of such higher order CROWe's for applications in non-Hermitian photonics, i.e., in which gain in some of the component MRRs and loss in the others leads to Parity-Time (PT) symmetry.
Comments9 pages, 11 figures
