Carneiro Elisa F, Calliari Felipe, Amaral Gustavo C, Temporão Guilherme P
Appl Opt. 2017 Aug 20;56(24):6855-6860. doi: 10.1364/AO.56.006855.
We theoretically propose and experimentally validate a practical random bit generation method based on the detections of a coherent state in the few-photon regime by a gated single-photon threshold detector, operating at the telecom wavelength of 1550 nanometers. By fine tuning the mean number of photons per pulse of a laser beam directed to the single-photon detector, a 50-50 chance of detection or no-detection is reached; under this condition, detections inside the gate window are treated as "1"s, while "0"s are associated with the absence of detections. The same method could also be applied in a free-running single-photon detector for increased throughput by chopping the light signal instead of gating the detector. Both hardware implementations yielded bit strings, which were evaluated by a standard randomness test suite with good confidence. Despite the yet low rates achieved by the proposed method, its hardware compatibility with quantum key distribution setups makes it an interesting candidate for random number generation within the context of practical quantum communications.
我们从理论上提出并通过实验验证了一种实用的随机比特生成方法，该方法基于在1550纳米电信波长下，由门控单光子阈值探测器在少光子 regime 中对相干态的检测。通过微调指向单光子探测器的激光束每个脉冲的平均光子数，实现了50%的检测或未检测概率；在此条件下，门窗口内的检测被视为“1”，而“0”与未检测相关联。同样的方法也可以应用于自由运行的单光子探测器，通过斩波光信号而不是门控探测器来提高吞吐量。两种硬件实现都产生了比特串，并通过标准随机测试套件进行了评估，结果令人满意。尽管所提出的方法目前实现的速率仍然较低，但其与量子密钥分发设置的硬件兼容性使其成为实际量子通信背景下随机数生成的一个有趣候选方案。
