Xu Changlong, Yan Ke, Gu Chun, Yao Peijun, Xu Lixin, Zhan Qiwen
Opt Lett. 2018 Mar 15;43(6):1247-1250. doi: 10.1364/OL.43.001247.
We report a novel method of beam shaping in an all-fiber laser. Flattop beams are first generated from the all-fiber laser using a few-mode fiber Bragg grating by superposing the fundamental mode (LP) with a solid central beam distribution, and the second-order mode (LP) gives rise to a donut-shape beam distribution. Two modes are obtained in the fiber laser simultaneously, and the wavelengths of the two modes are 1053.7 nm and 1055.4 nm, respectively. An experiment has been carried out, and a high-quality flattop profile is obtained for the normalized root-mean-square of the light intensity less than 5% under no numerical aperture illumination, consistent with the theoretical prediction.
我们报道了一种全光纤激光器中光束整形的新方法。首先通过使用少模光纤布拉格光栅，将基模（LP）与具有实心中心光束分布的光束叠加，从全光纤激光器中产生平顶光束，二阶模（LP）产生环形光束分布。在光纤激光器中同时获得了两种模式，这两种模式的波长分别为1053.7纳米和1055.4纳米。进行了一项实验，在无数值孔径照明的情况下，光强归一化均方根小于5%，获得了高质量的平顶分布，与理论预测一致。
