Alagappan G, García-Vidal F J, Png C E
<a href="https://ror.org/02n0ejh50">Institute of High-Performance Computing</a>, Agency for Science, Technology, and Research (A-STAR), Fusionopolis, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632, Singapore.
Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), <a href="https://ror.org/01cby8j38">Universidad Autónoma de Madrid</a>, E-28049 Cantoblanco, Madrid, Spain.
Phys Rev Lett. 2024 Nov 29;133(22):226901. doi: 10.1103/PhysRevLett.133.226901.
In this study, we construct Fabry-Perot cavities in which nanostructured, thin resonant metasurfaces act as mirrors. We develop a temporal coupled-mode theory and provide an accurate description of the resonances supported by these cavities, deriving analytically their transmission characteristics. The presence of metasurface mirrors introduces a substantial group delay, causing the field concentration to shift from the bulk of the cavity towards the regions close to the two metasurfaces. This shift is accompanied by a significant increase in the quality factor of the resonances that is associated with the emergence of singular points in frequency space. These singular points exist even when the cavity separations are smaller than the cavity length of the fundamental mode in standard cavities, enabling meta-mirror Fabry-Perot cavities to outperform traditional cavities by achieving much higher quality factors despite displaying shorter cavity lengths.
在本研究中，我们构建了法布里 - 珀罗腔，其中纳米结构的薄共振超表面充当镜子。我们发展了一种时间耦合模理论，并对这些腔所支持的共振提供了准确描述，通过解析推导得出它们的传输特性。超表面镜子的存在引入了显著的群延迟，导致场集中从腔的主体向靠近两个超表面的区域转移。这种转移伴随着共振品质因数的显著增加，这与频率空间中奇点的出现有关。即使腔间距小于标准腔中基模的腔长，这些奇点依然存在，使得元镜子法布里 - 珀罗腔尽管腔长较短，但通过实现更高的品质因数，性能优于传统腔。
