在分析光纤环形镜工作原理的基础上，给出了基于光纤环形镜的线形腔掺Er³⁺光纤激光器相位和幅度的振荡条件．通过求解速率方程，理论分析了其输出特性，获得了稳态条件下激光器输出功率、阈值泵浦功率和斜率效率的解析表达式．推导出激光器工作所需掺Er³⁺光纤最短长度，并在给定泵浦光功率时，在特定输出波长上获得最大输出功率所需最佳掺Er³⁺光纤长度的表达式，且通过实验进行了验证．

Based on the analyzing the principle of fiber loop mirror,the resonant conditions of phase and intensity of Linear Cavity Er³⁺ doped Fiber Laser Based on Fiber Loop Mirror are obtained. The output characteristics of continuous Er³⁺ doped linear cavity fiber laser based on fiber loop mirror have been theoretically studied and numerically analyzed by solving rate equations,and analytical expressions on laser output power,threshold pump power and slope efficiency under stationary condition have been derived. The expression of minimum and optimum fiber length for designing a linear cavity Er³⁺ doped fiber laser has been given,which will be helpful to the optimization of designing a practical linear cavity Er³⁺ doped fiber laser of the same kind based on fiber loop mirror. 1550 nm maximums fiber laser output of slope efficiency 18.3% have been obtained in the experiment.