光纤激光同带级联抽运的研究进展

Research Progress of Tandem-Pumped Fiber Lasers

光纤同带级联抽运的特点是以高亮度激光作为抽运光,且抽运光与激光的波长比较接近,处于激活离子的同一能带内。它最大的优点是在光纤高功率放大时量子亏损小,可以较好地减小热效应的影响,同时能使用较短的光纤来避免非线性效应的发生。针对同带级联抽运技术在高功率光纤中的重要性,简单综述了国外掺镱、掺铒、掺铥、掺钬光纤同带级联抽运的实验研究。给出了掺镱光纤同带级联抽运的其他优点,如抑制大模场面积光纤的高阶模式增益以及减少铝硅酸盐掺镱光纤中的光子暗化影响,这些优点都有助于光纤高功率的放大。讨论了掺镱同带级联抽运技术在高功率双包层光纤激光中面临的主要问题及解决方法。

High-brightness in-band pumping sources are used in tandem-pumping. It makes it possible to pump close to the emission wavelength, so the quantum defect heating can be low. This allows for the use of a shorter fiber. Therefore, it is easier to avoid thermal and nonlinear limits simultaneously. In view of the important of tandempumping in high power fiber laser, the experimental researches of tandem-pumped over seas are introduced firstly, including Yb-doped, Er-doped, Tin-doped, Ho-doped fiber lasers. Then the advantages such as restraining unwanted excess gain for higher order modes in cladding-pumped large-core Yb-doped fiber amplifiers are presented. And the potential benefits of reducing fiber photodarkening are also analyzed. At last, the problem and techniques of the tandem-pumping in high power fiber lasers are discussed.