Quantum key distribution (QKD) provides a solution for communication of unconditional security. However, the quantum channel disturbance in the field severely increases the quantum bit-error rate, degrading the performance of a QKD system. Here we present a setup comprising silica planar light wave circuits (PLCs), which is robust against the channel polarization disturbance. Our PLCs are based on the asymmetric Mach–Zehnder interferometer (AMZI), integrated with a tunable power splitter and thermo-optic phase modulators. The polarization characteristics of the AMZI PLC are investigated by a novel pulse self-interfering method to determine the operation temperature of implementing polarization insensitivity. Over a 20 km fiber channel with 30 Hz polarization scrambling, our time-bin phase-encoding QKD setup is characterized with an interference fringe visibility of 98.72%. The extinction ratio for the phase states is kept between 18 and 21 dB for 6 h without active phase correction.

中文翻译：

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基于二氧化硅光子学的单光子能级抗干扰能力强

量子密钥分发（QKD）提供了无条件安全通信的解决方案。但是，现场中的量子信道干扰会严重增加量子误码率，从而降低QKD系统的性能。在这里，我们介绍一种包含二氧化硅平面光波电路（PLC）的设置，该设置可抵抗通道极化干扰。我们的PLC基于非对称马赫曾德尔干涉仪（AMZI），并与可调功率分配器和热光相位调制器集成在一起。通过一种新型的脉冲自干扰方法研究了AMZI PLC的偏振特性，以确定实现偏振不敏感的工作温度。在20 km的光纤通道上，极化扰频为30 Hz，我们的时区相位编码QKD设置具有98.72％的干涉条纹可见度。在不进行主动相位校正的情况下，相位状态的消光比在18至21 dB之间保持6小时。