为避免时域调制增长形成的高强度时间尖峰对光学元件的损坏,数值研究了啁啾堆积脉冲宽带激光非线性传输的时域调制增长规律。结果表明:对于正常色散介质, 子脉冲间干涉引入的时间调制与外加调制随着传输距离的增加, 不断振荡减弱; 相反, 对于反常色散介质, 无外加时间噪声时, 堆积子脉冲间的相互干涉引入的时间调制有微弱增长, 但当传输距离进一步增加时, 子脉冲间干涉引入的调制可以获得快速增长; 而当外加非线性最快增长时间调制时, 时间调制发生迅速增长,具有破坏威胁的时间尖峰易于形成。

Characteristics of the temporal modulation riding on broad-band lasers stacked by chirped pulses are numerically investigated in nonlinear propagation. For the case of normal dispersion, the temporal modulations induced by interference among pulses and added artificially to simulate the noise weaken gradually with the increase of the propagation distance. For the case of anomalous dispersion, the temporal modulations induced by interference among pulses grow slowly at first, and start to grow rapidly after a long propagation distance; in contrast, the temporal modulations added artificially grow rapidly from the begin, indicating that the temporal peak of damage risk to the optics can be formed easily.