光纤激光谱合成改善光束质量的研究进展

Research progresson improving beam quality of spectral beam combining for fiber laser

光束质量是衡量激光性能的重要指标。鉴于当前谱合成光束质量的研究现状,本文归纳出3种改善光束质量的方法:窄线宽法,双光栅色散补偿法,抑制光栅热变形法。对于每一种方法,详细介绍了其设计思路;综述了该思路下光束质量改善所取得的进展。此外,本文还展示了我们团队研究光栅热变形、影响光束质量的理论和实验成果。该成果表明:在30 W激光辐照下,2 min内,M^(2)从1.06增加到1.26。显示出谱合成的光束质量是一个动态变化过程。

Beam quality is an important index to evaluate the performance of laser.In view of the current research status of beam quality in spectral beam combining, three different schemes to improve beam quality are summarized in this paper, which included the scheme of narrow linewidth, dispersion compensation by dual-grating, and suppressing grating thermal deformation.For each scheme, the design technique is introduced in detail, the achieved results of improving beam quality are summarized.Furthermore, this paper also presents the theoretical and experimental results that our team investigated the thermal deformation of the grating on beam quality degradation.It shows that the M^(2) increases from 1.06 to 1.26 within 2 min when the irradiation power was 30 W,indicating that the beam quality of spectral beam combining is a dynamic process.