介绍了使用飞秒锁模激光实现稳定的时间频率传输的实验进展。采用1.2 km通信光纤传输89.7 MHz飞秒激光脉冲,同时其中插入一个主动延迟线,通过比较光纤返回的脉冲信号与激光器本地信号的第10次谐波的相位,将180 ps的时延补偿到了36 ps,证明了此方法在光纤传输时频信号的有效性。理论上本系统的延迟时间测量分辨率应为10 fs,由于噪声的原因,实际分辨率有所降低。进一步的工作正在进行,以提高信噪比和系统的稳定性。

We report the experimental progress of the timing distribution system with a femtosecond laser. For the pulses at repetition rate of 89.7 MHz from a femtosecond fiber laser as the timing signal,and with an active variable timing delay line,we reduced the timing delay from 180 ps to 36 ps,by comparing the phase of the 10th hamonic repetition rate of the fiber laser with the feedbacked pulse signal. The results proved the technique to be effective for delay compensation in a timing distribution system. The theoretical prediction of the resolution of the sysytem should be in the order of 10 fs. The noise makes the actual resolution greater than 10 fs. Further experiment is going on to improve signal-to-noise ratio and the the system stability.