Characterising a handheld quantum key distribution system with emulated beam steering
Characterising a handheld quantum key distribution system with emulated beam steering
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DOI：
10.1117/12.2603355
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发表时间：
2021-10
期刊：
影响因子：
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通讯作者：
D. Lowndes;A. Schreier;D. O’brien;J. Rarity
中科院分区：
文献类型：
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作者：
D. Lowndes;A. Schreier;D. O’brien;J. Rarity
我们提出了一种小型化自由空间量子密钥分发（QKD）系统，该系统允许手持发射器和固定终端之间进行密钥交换。 QKD 系统需要进行光学对准，这强调了后续应用需要光束控制单元。为了保持尺寸、重量和功率限制，有源波束控制硬件专门位于接收器内部。我们的目标是消费者使用，因此我们针对一系列背景光水平进行严格的表征，以显示实验室环境之外的预期性能。实验结果表明，原始计数率随添加组件的传输量相应降低（74.5%），并且由于信噪比较差，错误率略有下降（0.5 个百分点）。加上用于波束控制的附加组件，系统的估计密钥率可降低 50%。
We present a miniaturised free-space quantum key distribution (QKD) system which allows key exchange between a handheld transmitter and a fixed terminal. The QKD system requires to be optically aligned emphasising the need of a beamsteering unit for later applications. To maintain within the size, weight and power restrictions, the active beamsteering hardware is exclusively located inside the receiver. Our target is consumer use so we present rigorous characterisation against a range of background light levels to show anticipated performance outside of a laboratory environment. Experimental results show a reduction in the raw count rate commensurate with the transmission of the added components (74.5%) and a small degradation of the error rate (0.5 percentage points) due to the worse signal-to-noise ratio. These combine to a 50% reduction in estimated secret key rate of the system with the additional components for beam steering.