对三能级光纤激光器速率方程组的分析

Analyses of Rate Equations of Fiber Lasers with Three-Energy-Level Dopants

摘要: 对三能级光纤激光器的速率方程组进行了分析。在恒定泵浦功率的情况下，求解了三能级光纤激光器的速率方程组，获得了三能级光纤激光器的单位阶跃响应。并利用三能级光纤激光器的单位阶跃响应对三能级光纤激光器的输出特性进行了研究，研究表明：三能级光纤激光器的输出特性取决于三能级光纤激光器的阻尼比ξ。对于不同的阻尼比，可以得到不同阻尼的衰减振荡曲线以及过阻尼时的单调衰减曲线。当0 < ξ < 1时，三能级光纤激光器受激辐射的单位光子数密度将以频率ωd做衰减振荡。当ξ = 1或ξ > 1时，三能级光纤激光器受激辐射的单位光子数密度将无振荡单调上升。

Abstract: The rate equations of fiber lasers with three-energy-level dopants are anglicized. An expression of the unit step response of the fiber laser with three-energy-level dopants has been obtained from rate equations in a constant pump power. With these expressions, output characteristic of the fiber laser with three-energy-level dopants has been studied. The output characteristic of the fiber laser with three-energy-level dopants depends on its damping ratio, and the different damped oscillation curves and over-damped monotonic decay curves can be obtained for various damping ratio of the fiber laser with three-energy-level dopants. If 0 < ξ < 1, the photon density curves of stimulated radiation of the fiber laser will be a damping oscillation curves. If ξ = 1 or ξ > 1, the photon density curves of stimulated radiation of the fiber laser will be non-oscillating monotonic decay curves.