Opt Lett. 2018 Jul 15;43(14):3369-3372. doi: 10.1364/OL.43.003369.
We investigate mode-area scaling by means of supermode operation in an all-solid multicore fiber. To obtain a large-mode area (LMA), we designed and fabricated an active double-clad multicore fiber, where each ytterbium-doped core is 19 μm in diameter and has a numerical aperture of 0.067, comparable to the core of the largest available commercial LMA fibers. The six large cores are stacked tightly in a ring structure to enable phase locking of the core fields and supermode operation. The fiber laser performance was investigated in a linear laser cavity with an external Talbot resonator for mode selection. The highest output power achieved was 115 W with an overall 61% slope efficiency corresponding to the pump power. The measured M was 1.43 for the central lobe with nearly 70% of the total power.
我们通过全固态多芯光纤中的超模操作研究模式面积缩放。为了获得大模式面积（LMA），我们设计并制造了一种活性双包层多芯光纤，其中每个掺镱芯的直径为 19μm，数值孔径为 0.067，与最大可用商业 LMA 光纤的芯径相当。六个大芯紧密堆叠成一个环形结构，以实现芯场的相位锁定和超模操作。光纤激光器的性能在具有外部塔波特谐振器的线性激光腔中进行了研究，以进行模式选择。在最高输出功率为 115W 的情况下，总斜率效率为 61%，对应于泵浦功率。测量的 M 值为中心瓣的 1.43，总功率的近 70%。
