整形飞秒激光脉冲在熔融石英中的成丝控制研究

Control of Filament by Shaped Femtosecond Pulses in Fused Silica

利用基于液晶空间光调制器的飞秒激光脉冲整形技术,对飞秒激光在熔融石英中形成等离子体丝的过程进行优化控制研究。实验结果表明:通过脉冲整形可以在固体介质中的指定位置产生等离子体丝。实现了整形脉冲在熔融石英中成丝起点的长距离可控移动,最大移动量达到5.4 mm。通过求解(3+1)维非线性薛定谔方程,对整形脉冲在熔融石英中的成丝过程进行理论模拟研究,得到了与实验一致的结果。研究结果表明:等离子体丝起始位置是由整形飞秒脉冲的中心峰值强度和包络分布决定的。

The pulse shaping technology based on liquid crystal spatial light modulator is used to control the femtosecond laser filament in fused silica. The experimental results show that the filament can be generated at a designated position in fused silica. In addition, a long-distance controllable displacement of the onset of filamentation in fused silica is achieved, with a maximum displacement of 5.4 mm. Furthermore, the theoretical simulation on filamentation of shaped pulse in fused silica is performed based on the(3 + 1)-D nonlinear Schr(o|¨)dinger equation.The results are consistent with those of experiments. It is demonstrated that the onset of filamentation depends on the peak intensity and envelope of shaped femtosecond pulse.