中文摘要：

研究了单端泵浦条件下掺Nd^3＋增益导引-折射率交叉导引（GG-ICG）光纤激光器的阈值特性。建立了单端泵浦条件下改进的速率方程,通过解析解得到了阈值泵浦功率,并分析了阈值泵浦功率与Nd^3＋掺杂浓度（N）,光纤长度（L）,纤芯半径（a）以及输出镜反射率（R2s）之间的关系,并给出了理论解释。研究结果表明,当N=1×10^20cm^-3,L=1 cm,a=45μm,R1s=1,R2s=0.85时,对应的激光阈值最低,为2.95 W。研究结果对光纤激光器的优化设计具有重要的意义。

英文摘要：

The threshold characteristics of Nd^3＋-doped gain-guided index-crossover guided（ GG-ICG） fiber lasers under the end-pumped condition are investigated. The threshold equation is deduced from the rate equations. The effects of Nd^3＋concentration（ N）,fiber length（ L）,core radius（ a）,and mirror reflectivity（ R2s） on the threshold pump power are discussed. The results show that when N =1 ×10^20cm^-3,L = 1 cm,a = 45 μm,R1s= 1,and R2s= 0. 85,the threshold pump power is the lowest,2. 95 W. It has important significance for the optimal design of the fiber laser.