Krutyanskiy V, Meraner M, Schupp J, Lanyon B P
1Institut für Quantenoptik und Quanteninformation, Technikerstrasse 21a, 6020 Innsbruck, Austria.
2Institute for Experimental Physics, University of Innsbruck, 6020 Innsbruck, Austria.
Appl Phys B. 2017;123(9):228. doi: 10.1007/s00340-017-6806-8. Epub 2017 Aug 18.
We demonstrate polarisation-preserving frequency conversion of single-photon-level light at 854 nm, resonant with a trapped-ion transition and qubit, to the 1550-nm telecom C band. A total photon in / fiber-coupled photon out efficiency of 30% is achieved, for a free-running photon noise rate of 60 Hz. This performance would enable telecom conversion of 854 nm polarisation qubits, produced in existing trapped-ion systems, with a signal-to-noise ratio greater than 1. In combination with near-future trapped-ion systems, our converter would enable the observation of entanglement between an ion and a photon that has travelled more than 100 km in optical fiber: three orders of magnitude further than the state-of-the-art.
我们展示了将与捕获离子跃迁和量子比特共振的854纳米单光子水平光的保偏频率转换到1550纳米电信C波段。在自由运行光子噪声率为60赫兹的情况下，实现了总光子输入/光纤耦合光子输出效率为30%。这种性能将使现有捕获离子系统中产生的854纳米偏振量子比特能够进行电信转换，信噪比大于1。与不久的将来的捕获离子系统相结合，我们的转换器将能够观测到在光纤中传播超过100公里的离子与光子之间的纠缠：比目前的技术水平远三个数量级。
