Zahidy Mujtaba, Liu Yaoxin, Cozzolino Daniele, Ding Yunhong, Morioka Toshio, Oxenløwe Leif K, Bacco Davide
Center for Silicon Photonics for Optical Communications (SPOC), Department of Photonics Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark.
Nanophotonics. 2021 Nov 30;11(4):821-827. doi: 10.1515/nanoph-2021-0500. eCollection 2022 Jan.
Light carrying orbital angular momentum constitutes an important resource for both classical and quantum information technologies. Its inherently unbounded nature can be exploited to generate high-dimensional quantum states or for channel multiplexing in classical and quantum communication in order to significantly boost the data capacity and the secret key rate, respectively. While the big potentials of light owning orbital angular momentum have been widely ascertained, its technological deployment is still limited by the difficulties deriving from the fabrication of integrated and scalable photonic devices able to generate and manipulate it. Here, we present a photonic integrated chip able to excite orbital angular momentum modes in an 800 m long ring-core fiber, allowing us to perform parallel quantum key distribution using two and three different modes simultaneously. The experiment sets the first steps towards quantum orbital angular momentum division multiplexing enabled by a compact and light-weight silicon chip, and further pushes the development of integrated scalable devices supporting orbital angular momentum modes.
携带轨道角动量的光构成了经典和量子信息技术的重要资源。其固有的无界性质可被用于生成高维量子态，或用于经典和量子通信中的信道复用，以便分别显著提高数据容量和密钥率。虽然拥有轨道角动量的光具有巨大潜力已得到广泛确认，但其技术应用仍受到能够产生和操纵它的集成且可扩展光子器件制造困难的限制。在此，我们展示了一种光子集成芯片，它能够在一根800米长的环形纤芯光纤中激发轨道角动量模式，使我们能够同时使用两种和三种不同模式进行并行量子密钥分发。该实验朝着由紧凑且轻便的硅芯片实现的量子轨道角动量波分复用迈出了第一步，并进一步推动了支持轨道角动量模式的集成可扩展器件的发展。
