啁啾脉冲堆积宽带激光非线性传输空间调制特性

摘要

To identify the potential risks of spatial modulation of broad-band laser beams stacked by chirped pulses on the safety of optics, this paper numerically investigated the effect of temporal modulation on the generation and growth of spatial modulation during its nonlinear propagation.When there is no additional spatial modulation and the B integral is limited in the practical working range (usually less than 2.0 rad), no spatial modulation will be generated for both normal dispersion and anomalous dispersion; while with the B integral further increasing, spatial modulation will emerge with a rapid growth.When there is additional spatial modulation for anomalous dispersion, the spatial modulation with additional temporal modulation will grow more quickly than that without additional temporal modulation.However, for normal dispersion, the growth of spatial modulation for both cases is similar.%为避免啁啾脉冲堆积宽带激光的空间调制对光学元件的损坏,数值研究了其非线性传输过程中时域调制对光束空间调制产生与增长的影响.结果表明:光束未叠加空间调制时,若B积分在实际工作范围内,堆积子脉冲间干涉引入时间调制外,叠加与未叠加时间调制,正反常色散情况下光束空间上均不会产生调制,因而也没有调制增长,然而,当B积分进一步增加时,光束空间将产生调制,并能快速增长;当光束引入空间调制后,在反常色散情况下,与时间未额外叠加调制相比,时间额外叠加调制时空间调制增长速度明显加快,而在正常色散时,额外添加时间调制与不添加调制,空间调制增长的差别很小.