高功率光子晶体光纤放大器内超短脉冲的放大传输特性

Amplification and Propagation of Ultrashort Pulse in High Power Photonic Crystal Fiber Amplifier

由速率方程和功率传输方程得到信号脉冲平均功率和增益系数随脉冲传输距离的变化关系.利用Ginzburg-landau方程,在信号脉冲功率的不断增强和增益系数的不断变化的情况下,研究超短脉冲的传输演化特性,发现信号脉冲平均功率、能量和增益系数等参量受到色散和非线性效应的影响相对较小,而信号脉冲的峰值功率、时域和频域特性则易受到色散和非线性效应的影响.探讨了在非线性作用下,脉冲分裂和展宽等所导致的脉宽不稳定性对传输特性的影响,表明研究脉冲传输问题时,引入脉宽不稳定性有利于提高数值模拟准确度.

The dependences of the signal pulse average power and gain coefficient on the distance are obtained by using the rate equations and power propagation equations,and the Ginzburg-landau equation is employed to study the propagation of the ultrashort pulse. The results show that parameters suchlike signal pulse average power,energy and gain coefficient are not susceptible to the dispersion and nonlinear effect, while signal pulse peak power, and the characteristics of time and frequency domain are easy to be affected by the dispersion and nonlinear effect. The instability of pulse width caused by pulse splitting and broadening and the effect of the instability on pulse propagation are analyzed and discussed under the consideration of the nonlinear effect. It reveals that the accuracy of numerical simulation can be improved by introducing the pulse width instability in the study of the pulse propagation.