近日，重庆工商大学袁利军团队研究了周期结构中单向导向共振的参数依赖性。2025年10月28日出版的《物理评论A》杂志发表了这项成果。

周期结构中的单向引导共振（UGRs）是一种特殊的共振模式，即使允许两侧辐射，也表现出严格的单侧辐射，为各种应用提供了显著优势。在结构扰动下，UGR通常转向向两侧辐射的规则共振模式。已有的数值结果表明，要在任意周期结构中找到UGRs，至少需要对一个参数进行调优。

在这项工作中，研究组建立了一个严格的理论，即关于UGRs的参数依赖性。研究组证明了在单一辐射通道存在的情况下，如果另一个参数（与一般扰动相关）被适当调谐，则UGR可以相对于结构参数连续存在。此外，对于连续统（BIC）中具有一般束缚态的周期结构，通过调整一个参数总是可以得到连续的UGRs族。这意味着可以很容易地获得任意大质量因子的UGRs。该工作为设计基于UGRs的光子器件提供了理论基础。

附：英文原文

Title: Parametric dependence of unidirectional guided resonances in periodic structures

Author: Lijun Yuan, Ya Yan Lu

Issue&Volume: 2025/10/28

Abstract: Unidirectional guided resonances (UGRs) in periodic structures are special resonant modes that exhibit strict one-sided radiation, even though radiation in both sides is allowed, offering significant advantages for various applications. Under a structural perturbation, a UGR typically turns to a regular resonant mode that radiates to both sides. Existing numerical results indicate that to find UGRs in any periodic structure, it is necessary to tune at least one parameter. In this work, we develop a rigorous theory on the parametric dependence of UGRs. We show that in the presence of a single radiation channel, a UGR can exist continuously with respect to a structural parameter, provided that another parameter (associated with a generic perturbation) is properly tuned. Moreover, from a periodic structure with a generic bound state in the continuum (BIC), it is always possible to obtain a continuous family of UGRs by tuning one parameter. This implies that UGRs with arbitrarily large quality factor can be easily obtained. Our work provides a theoretical basis for designing useful photonic devices based on UGRs.

DOI: 10.1103/jgd6-t8yp

Source: https://journals.aps.org/pra/abstract/10.1103/jgd6-t8yp