An efficient atom–photon interface is a key requirement for the integration of solid-state emitters, such as color centers in diamond, into quantum technology applications. As other solid-state emitters, however, their emission into free space is severely limited due to the high refractive index of the bulk host crystal. In this work, we present a planar optical antenna based on two silver mirrors coated on a thin single crystal diamond membrane, forming a planar Fabry–Pérot cavity that improves the photon extraction from single tin vacancy (SnV) centers and their coupling to an excitation laser. Upon numerical optimization of the structure, we find theoretical enhancements in the collectible photon rate by a factor of 60 as compared to the bulk case. As a proof-of-principle demonstration, we fabricate single crystal diamond membranes with sub-μm thickness and create SnV centers by ion implantation. Employing off-resonant excitation, we show a sixfold enhancement of the collectible photon rate, yielding up to half a million photons per second from a single SnV center. At the same time, we observe a significant reduction of the required excitation power in accordance with theory, demonstrating the functionality of the cavity as an optical antenna. Due to its planar design, the antenna simultaneously provides similar enhancements for a large number of emitters inside the membrane. Furthermore, the monolithic structure provides high mechanical stability and straightforwardly enables operation under cryogenic conditions as required in most spin–photon interface implementations.

中文翻译：

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一种基于腔体的金刚石色心光学天线

高效的原子-光子界面是将固态发射器（例如金刚石中的色心）集成到量子技术应用中的关键要求。然而，与其他固态发射器一样，由于主体晶体的高折射率，它们向自由空间的发射受到严重限制。在这项工作中，我们提出了一种基于涂覆在薄单晶金刚石膜上的两个银镜的平面光学天线，形成平面法布里-珀罗腔，改善了从单锡空位 (SnV) 中心的光子提取及其与激发的耦合激光。在对结构进行数值优化后，我们发现与大块情况相比，可收集光子率的理论提高了 60 倍。作为原理验证演示，我们制造了具有亚μ m 厚度并通过离子注入创建 SnV 中心。采用非共振激发，我们展示了可收集光子速率的六倍增强，从单个 SnV 中心每秒产生多达 50 万个光子。同时，我们观察到根据理论所需的激励功率显着降低，证明了腔体作为光学天线的功能。由于其平面设计，天线同时为膜内的大量发射器提供类似的增强。此外，整体结构提供了高机械稳定性，并且可以直接在大多数自旋光子接口实现中要求的低温条件下运行。