采用化学气相沉积结合气相/液相复合掺杂方式制备30/600 μm掺镱双包层光纤, 石英纤芯中的掺杂组分为Yb2O3, Al2O3, P2O5。基于976 nm发光二极管反向抽运方式, 构建全光纤化的主控振荡器功率放大器结构对增益光纤进行测试。实验中, 种子源功率为189 W, 当泵浦总功率为4747 W时, 激光输出功率为4120 W, 放大级光光效率为85%, 3 dB带宽为1.6 nm。激光器连续工作1 h, 激光功率稳定在4100 W, 未发生明显的功率衰退现象。

A high power 30/600 μm ytterbium doped double-cladding fiber with excellent power stability was fabricated by MCVD in-situ vapor phase/solution doping technology. The dopants of the silica fiber core include Yb2O3, Al2O3 and P2O5. The master oscillator power amplifier configuration based on back pump was constructed to test the Yb-doped fiber performance. In the experiment, the power of the seed was 189 W, the total power of the pump power was 4767 W, and the maximum output power was 4120 W with a slope efficiency of 85%. In addition, no stimulated Raman scattering was found in the output laser spectrum, and the 3dB band width was measured to be 1.6 nm. The fiber laser continued to work for one hour, the output power was stable at 4.1 kW.