Rickert Lucas, Żołnacz Kinga, Vajner Daniel A, von Helversen Martin, Rodt Sven, Reitzenstein Stephan, Liu Hanqing, Li Shulun, Ni Haiqiao, Wyborski Paweł, Sęk Grzegorz, Musiał Anna, Niu Zhichuan, Heindel Tobias
Institute of Solid State Physics, Technical University Berlin, Hardenbergstraße 36, 10623 Berlin, Germany.
Department of Optics and Photonics, Wroclaw University of Science and Technology, Wybrzeże Stanisława Wyspiańskiego 27, 50-370 Wroclaw, Poland.
Nanophotonics. 2025 Jan 6;14(11):1795-1808. doi: 10.1515/nanoph-2024-0519. eCollection 2025 Jun.
Solid-state quantum light sources based on semiconductor quantum dots (QDs) are increasingly employed in photonic quantum information applications. Especially when moving towards real-world scenarios outside shielded lab environments, the efficient and robust coupling of nanophotonic devices to single-mode optical fibers offers substantial advantage by enabling "plug-and-play" operation. In this work we present a fiber-pigtailed cavity-enhanced source of flying qubits emitting single indistinguishable photons at clock-rates exceeding 1 GHz. This is achieved by employing a fully deterministic technique for fiber-pigtailing optimized QD-devices based on hybrid circular Bragg grating (hCBG) micro-cavities. The fabricated fiber-pigtailed hCBGs feature emission lifetimes of ps, corresponding to a Purcell factor of ∼9, a suppression of multi-photon emission events with (0) < 1 %, a photon-indistinguishability % and a measured single-photon coupling efficiency of 53 % in a high numerical aperture single-mode fiber, corresponding to 1.2 Megaclicks per second at the single-photon detectors under 80 MHz excitation clock-rates. Furthermore, we show that high multi-photon suppression and indistinguishability prevail for excitation clock-rates exceeding 1 GHz. Our results show that Purcell-enhanced fiber-pigtailed quantum light sources based on hCBG cavities are a prime candidate for applications of quantum information science.
基于半导体量子点（QD）的固态量子光源越来越多地应用于光子量子信息领域。特别是在迈向屏蔽实验室环境之外的实际场景时，纳米光子器件与单模光纤的高效且稳健的耦合通过实现“即插即用”操作提供了显著优势。在这项工作中，我们展示了一种尾纤式腔增强飞行量子比特源，它能以超过1GHz的时钟速率发射单光子，且这些光子不可区分。这是通过采用一种完全确定性的技术实现的，该技术用于基于混合圆形布拉格光栅（hCBG）微腔的尾纤式优化量子点器件。所制备的尾纤式hCBG具有皮秒级的发射寿命，对应于约9的珀塞尔因子，多光子发射事件的抑制率为（0）<1%，光子不可区分度为%，并且在高数值孔径单模光纤中测得的单光子耦合效率为53%，在80MHz激发时钟速率下，单光子探测器每秒可记录1.2兆次点击。此外，我们表明，对于超过1GHz的激发时钟速率，高多光子抑制和不可区分性依然存在。我们的结果表明，基于hCBG腔的珀塞尔增强型尾纤式量子光源是量子信息科学应用的主要候选者。
