Lai Wenchang, Ma Pengfei, Liu Wei, Huang Long, Li Can, Ma Yanxing, Zhou Pu
Opt Express. 2020 Jul 6;28(14):20908-20919. doi: 10.1364/OE.395619.
In this paper, we report a high power single frequency 1030 nm fiber laser with near-diffraction-limited beam quality based on a polarization-maintaining tapered Yb-doped fiber (T-YDF). The T-YDF has advantages of effectively suppressing stimulated Brillouin scattering (SBS) while maintaining good beam quality. As a result, a record output power of 379 W single frequency, linearly polarized, nearly single-mode fiber amplifier operating at 1030 nm is demonstrated. The polarization extinction ratio is as high as 16.3 dB, and the M is measured to be 1.12. Further, the dependence of the thermal-induced mode instability (TMI) threshold on the polarization state of an input signal laser is investigated for the first time. By changing the polarization state of the injected seed laser, the output power can increase to 550 W while the beam quality can be maintained well (M=1.47). The slope efficiency of the whole amplifier is about 80%. No sign of SBS appears even at the highest output power and the further brightness scaling of both situations is limited by the TMI effect. To the best of our knowledge, this result is the highest output power of all-fiberized single frequency fiber amplifiers.
在本文中，我们报道了一种基于保偏锥形掺镱光纤（T-YDF）的具有近衍射极限光束质量的高功率单频1030nm光纤激光器。该T-YDF具有在保持良好光束质量的同时有效抑制受激布里渊散射（SBS）的优点。结果表明，实现了一台工作在1030nm的单频、线性偏振、近单模光纤放大器379W的创纪录输出功率。偏振消光比高达16.3dB，测得的M²为1.12。此外，首次研究了热致模式不稳定性（TMI）阈值对输入信号激光偏振态的依赖性。通过改变注入种子激光的偏振态，输出功率可提高到550W，同时光束质量能得到很好的保持（M²=1.47）。整个放大器的斜率效率约为80%。即使在最高输出功率下也未出现SBS迹象，两种情况下进一步的亮度提升均受TMI效应限制。据我们所知，该结果是全光纤化单频光纤放大器的最高输出功率。
