双包层Er3+ /Yb3+共掺光纤激光器粒子数空间分布特性研究

针对双包层光纤激光器内包层和纤芯中光强的不同分布，基于速率方程，研究了不同泵浦方式下双包层Er^3＋／Yb^3＋共掺光纤激光器上能级粒子数的空间分布。结果表明：无论采用何种泵浦方式，沿光纤的径向，越接近于纤芯中心处，上能级粒子数越低；越接近于纤芯边缘，上能级粒子数越高。沿光纤轴向，激光输出端归一化的上能级粒子数总是少于非输出端归一化的上能级粒子数。

Study of Three-dimensional Distribution of Inverted Population in Er3+ /Yb3+ Co-doped Double-clad Fiber Laser

The electromagnetic field distribution, which decides population distribution of upper level, is different in first clad and core for double-clad fiber laser. Based on rate equation,three-dimensional distribution of inverted population is studied in Er3 /Yb3 co-doped double-clad fiber laser. The result shows that population in center of the core is lower than that in edge of the core along the fiber diameter, and normalized population at laser output end is also lower than that at other end along the fiber length.