We reported an all-polarization-maintaining single-frequency ytterbium-doped bidirectional fiber laser for the first time, to the best of our knowledge. Single-frequency operation was achieved by a stable dynamic grating in the active fiber of a proper length owing to the bidirectional operation of the laser. The fiber laser possesses a linewidth of 7.43 kHz, a slope efficiency of 47.9%, and a great long-term stability.

中文翻译：

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单频全保偏掺bi双向光纤激光器

据我们所知，我们首次报告了一种全偏振保持单频掺-双向光纤激光器。由于激光器的双向工作，通过在有源光纤中以适当长度的稳定动态光栅实现了单频工作。光纤激光器的线宽为7.43 kHz，斜率效率为47.9％，并且具有很高的长期稳定性。