三阶色散对脉冲经光纤放大器后增益特性的影响

Effect of Initial TOD on the Gain Characters of Pulses Propagating Through a Fiber Amplifier

为研究限制啁啾脉冲放大(CPA)系统产生高能超短激光脉冲的可能因素,采用时间相关的非线性辐射迁移方程组描述掺镱光纤中脉冲的放大过程,并利用此模型分析了脉冲初始三阶色散(TOD)对脉冲经放大器传输后的功率增益特性的影响.数值结果表明,当入射脉冲能量相同时,初始TOD为0的脉冲放大后的输出峰值功率增益比具有正TOD的脉冲峰值功率增益小,却比TOD为负值的脉冲峰值功率增益大,并且增益值间的差别随脉冲初始能量的增大而增大.

The effect of the third order dispersion（TOD） in ultrashort pulses on power gain characters of them after propagating through a fiber amplifier in a chirped pulse amplification（CPA） system is investigated numerically.The pulse amplification process is described by nonlinear time-dependent radiation transfer equations.Simulations show that,when the energy of the input pulse is identical,the peak power gain for the pulse without TOD is smaller than that with positive TOD,but larger than that with negative TOD.And the difference between the gain values increases with the initial pulse energy.