【摘要】 基于高功率激光正支共焦非稳定谐振腔的特点,利用快速傅里叶变换,得到空心光束激光光场的远场分布,分析了远距离输送激光能量产生的激光烧蚀力学行为的演化过程.利用有限元法,数值仿真了烧蚀冲击波压强的时空演化过程,得到了烧蚀冲击波在ns激光脉冲照射下的空间压强分布随时间的变化关系.当激光谐振腔初始输出单脉冲激光能量为500 J,脉冲宽度为10 ns,脉冲关闭后延迟时间分别为80 ns,160 ns和240ns时,烧蚀表面产生的最大压强分别达到2.10 GPa,1.75 GPa和1.36 GPa.更多还原

【Abstract】 The far-field patterns of the laser field were obtained by means of fast Fourier transform(FFT) through a positive confocal unstable resonator,and the pressure evolvement characteristics of the shock wave induced by the laser ablation on the titanium target were analyzed and discussed.Using finite element method,the ablation pressure of the space-time evolution of shock waves was simulated,and the spatial pressure distribution changed with time relation in the nanosecond ablation of shock wave was obtained.When the output pulse laser energy from the resonator is 500 J and pulse duration 10 ns,the maximum pressure produced on the ablation surface is 2.10 GPa,1.75 GPa and 1.36 GPa respectively,for the delay time after the pulse of 80 ns,160 ns and 240 ns.更多还原