论文标题
纳米卫星的极化QKD的光学有效载荷的设计和测试
Design and test of optical payload for polarization encoded QKD for Nanosatellites
论文作者
论文摘要
低地球轨道（LEO）中基于卫星的量子键分布（QKD）是目前唯一可以跨越数千公里的可行技术。由于卫星的典型开销持续了几分钟，因此提高信号速率以最大化秘密钥匙长度至关重要。对于将在两年内推出的Quarc Cubesat任务，我们正在设计一个双波长，弱点 - 脉冲脉冲诱饵状态Bennett-Brassard '84（WCP DS BB84）QKD来源。光学有效载荷以$ 12 {\ times} 9 {\ times} 5 cm^3 $ BESPOKE铝制外壳设计。离散变量QKD源包括两个在785 nm和808 nm处运行的对称源。激光二极管分别固定以产生水平，垂直，对角线和抗diagonal（H，V，D，A）极化，它们合并并减弱至平均光子数为0.3和0.5光子/脉冲。我们通过空间模式过滤输出光束并表征其光谱和时间特征，确保源可抵抗大多数侧通道攻击。源的灭绝率以0.817 \ pm 0.001 \％$ $ 0.817 \％$促进了内在的Qubit错误率（QBER）。该来源的运行量为200MHz，足以提供每秒几公斤数量的安全关键率
Satellite based Quantum Key Distribution (QKD) in Low Earth Orbit (LEO) is currently the only viable technology to span thousands of kilometres. Since the typical overhead pass of a satellite lasts for a few minutes, it is crucial to increase the the signal rate to maximise the secret key length. For the QUARC CubeSat mission due to be launched within two years, we are designing a dual wavelength, weak-coherent-pulse decoy-state Bennett-Brassard '84 (WCP DS BB84) QKD source. The optical payload is designed in a $12{\times}9{\times}5 cm^3$ bespoke aluminium casing. The Discrete Variable QKD Source consists of two symmetric sources operating at 785 nm and 808 nm. The laser diodes are fixed to produce Horizontal,Vertical, Diagonal, and Anti-diagonal (H,V,D,A) polarisation respectively, which are combined and attenuated to a mean photon number of 0.3 and 0.5 photons/pulse. We ensure that the source is secure against most side channel attacks by spatially mode filtering the output beam and characterising their spectral and temporal characterstics. The extinction ratio of the source contributes to the intrinsic Qubit Error Rate(QBER) with $0.817 \pm 0.001\%$. This source operates at 200MHz, which is enough to provide secure key rates of a few kilo bits per second despite 40 dB of estimated loss in the free space channel
