Time transfer based on phase modulation schemes has attracted extensive attention in recent years. We propose and experimentally demonstrate an adjustable and stable Michelson interferometer (MI) with a DC phase tracking algorithm for two-way time transfer. Time signal with one pulse per second (1 PPS) is loaded on an optical carrier modulated in phase and demodulated by a Michelson interferometer. The whole compact and cost-effective demodulator is symmetrical with a single coupler to split and recombine optical waves, flexible with one photodetector and a bias tee to separate the DC signal and recovery pulses and stable with a phase modulator to compensate for the drift-phase noise. We show the implementation of modulation and demodulation of the time signal and obtain the stability of 2.31 × 10⁻¹¹ at 1000 s averaging time. We then demonstrate two-way time transfer over 1556 km lab fibers. The experimental result shows time interval stability of 1 PPS with 5.62 × 10⁻¹¹ at 1000 s averaging time. It has the potential to transfer time signals in long-distance fiber optic links.

中文翻译：

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基于迈克尔逊干涉仪的相位解调技术，可在1556公里光纤链路上实现稳定的时间传输

近年来，基于相位调制方案的时间转移引起了广泛的关注。我们提出并通过实验演示了一种可调稳定的迈克尔逊干涉仪（MI），该器件具有用于两个时间传递的DC相位跟踪算法。每秒具有一个脉冲（1 PPS）的时间信号被加载到同相调制的光载波上，并由迈克尔逊干涉仪进行解调。整个紧凑且经济高效的解调器采用单个耦合器对称，以分离和重组光波；通过一个光电检测器和一个偏置三通可灵活实现，以分离DC信号和恢复脉冲；并通过相位调制器稳定，以补偿漂移相位。噪音。我们展示了时间信号的调制和解调的实现，并获得了2.31×10 ^-11的稳定性平均时间为1000秒。然后，我们演示了在1556公里实验室光纤上的双向时间传输。实验结果表明，平均时间为1000 s时，具有5.62×10 ^-11的1 PPS的时间间隔稳定性。它具有在长距离光纤链路中传输时间信号的潜力。