Deterministic quantum dots (apex-QDs), which are spontaneously formed at the vertex of pyramid structures, are an attractive single-photon source. Herein, we propose the design of apex-QDs coupled to a single-mode optical fiber for directional emission from a quantum dot, followed by optimization of the structural parameters to maximize the extraction efficiency toward the fiber using FDTD simulation. A dielectric layer of SiO2 was inserted between a silver and a quantum dot to minimize the metallic loss and control the distance between them. For this, the optimum layer thicknesses of silver and SiO2 were 100 nm and 240 nm, respectively, achieving 94% light collection downward near 600 nm in wavelength. The proposed structure was then coupled to a tapered optical fiber, achieving 60% of the quantum dot emission. This high collection through an optical fiber was observed for a wide range of emission wavelengths.

中文翻译：

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从耦合到单模光纤的顶点量子点中有效地提取光

在金字塔结构的顶点自发形成的确定性量子点 (apex-QD) 是一种有吸引力的单光子源。在此，我们提出了与单模光纤耦合的顶点量子点设计，用于从量子点定向发射，然后优化结构参数以使用 FDTD 模拟最大化光纤的提取效率。在银和量子点之间插入一层 SiO2 介电层，以最大限度地减少金属损失并控制它们之间的距离。为此，银和 SiO2 的最佳层厚度分别为 100 nm 和 240 nm，在波长接近 600 nm 处实现了 94% 的向下光收集。然后将提议的结构耦合到锥形光纤，实现 60% 的量子点发射。