Chanana Ashish, Melo Emerson G, Davanco Marcelo
Opt Express. 2025 Jun 16;33(12):24831-24843. doi: 10.1364/OE.562994.
A key element for on-chip quantum photonic systems is a reliable source of on-demand, indistinguishable, waveguided single photons that can be seamlessly integrated with photonic circuits. While epitaxial semiconductor quantum dots have the potential to fulfill such needs, optical excitation that is resonant with the quantum dot ensures maximum single-photon indistinguishability. To date, a majority of waveguided quantum dot sources that allowed resonant excitation have relied on free-space excitation beams. Free-space excitation requires significant experimental overhead, especially if multiple sources need to be addressed. waveguided resonant excitation, in contrast, has not been extensively explored, and yet enables simplified, plug-and-play operation of single and even multiple sources on chip. Here, we show design steps for what we believe to be a novel, modular nanophotonic structure that, relying on inversely designed components, allows waveguided resonant quantum dot excitation with high single-photon waveguide collection efficiencies (> 85 %) and low multi-photon probability (<10), many favorable trade-off possibilities, and reasonable robustness to quantum dot positioning.
片上量子光子系统的一个关键要素是可靠的按需、不可区分、波导单光子源，该单光子源能够与光子电路无缝集成。虽然外延半导体量子点有潜力满足此类需求，但与量子点共振的光激发可确保最大程度的单光子不可区分性。迄今为止，大多数允许共振激发的波导量子点源都依赖自由空间激发光束。自由空间激发需要大量的实验开销，尤其是在需要处理多个源的情况下。相比之下，波导共振激发尚未得到广泛探索，但它能够实现芯片上单个甚至多个源的简化即插即用操作。在这里，我们展示了我们认为是一种新颖的模块化纳米光子结构的设计步骤，该结构依靠反向设计的组件，允许以高单光子波导收集效率（>85%）和低多光子概率（<10）进行波导共振量子点激发，具有许多有利的权衡可能性，并且对量子点定位具有合理的稳健性。
