An all-fiberized high-average-power narrow linewidth ns pulsed laser with linear polarization is demonstrated. The laser system utilizes a typical master oscillator power amplifier (MOPA) configuration. The stimulated Brillouin scattering (SBS) is effectively suppressed due to the short fiber length and large mode area in the main amplifier, combined with the narrow pulse duration smaller than the phonon lifetime of SBS effect. A maximal output power of 466 W is obtained with a narrow linewidth of ${\sim}$203.6 MHz, and the corresponding slope efficiency is ${\sim}$80.3%. The pulse duration is condensed to be ${\sim}$4 ns after the amplification, corresponding to the peak power of 8.8 kW and the pulse energy of $46.6~\unicode[STIX]{x03BC}\text{J}$. Near-diffraction-limited beam quality with an $M^{2}$ factor of 1.32 is obtained at the output power of 442 W and the mode instability (MI) is observed at the maximal output power. To the best of our knowledge, this is the highest average output power of the all-fiberized narrow linewidth ns pulsed fiber laser with linear polarization and high beam quality, which is a promising source for the nonlinear frequency conversion, laser lidar, and so on.

中文翻译：

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具有近衍射极限光束质量的单片高平均功率线偏振纳秒脉冲光纤激光器

展示了一种具有线偏振的全光纤高平均功率窄线宽纳秒脉冲激光器。激光系统采用典型的主振荡器功率放大器 (MOPA) 配置。受激布里渊散射 (SBS) 由于主放大器中的短光纤长度和大模式面积，以及小于 SBS 效应的声子寿命的窄脉冲持续时间而得到有效抑制。最大输出功率为 466 W，线宽为${\sim}$203.6 MHz，相应的斜率效率为${\sim}$80.3%。脉冲持续时间被压缩为${\sim}$放大后 4 ns，对应的峰值功率为 8.8 kW，脉冲能量为$46.6~\unicode[STIX]{x03BC}\text{J}$. 近衍射极限光束质量$M^{2}$在 442 W 的输出功率下获得了 1.32 的因子，并且在最大输出功率下观察到模式不稳定性 (MI)。据我们所知，这是具有线性偏振和高光束质量的全光纤窄线宽纳秒脉冲光纤激光器的最高平均输出功率，是非线性频率转换、激光激光雷达等有前途的光源.