强脉冲激光烧蚀铝靶深度历史的蒸发凝结法模拟

Calculation of History of Ablation Depth of Al Target Irradiated by Intense Pulsed Laser Using Evaporation-condensation Theory

为避免考虑强脉冲激光烧蚀过程涉及的复杂物理问题,提出一种用蒸发和凝结理论计算烧蚀坑深度历史的方法。给出了一定靶面压力和温度历史下的烧蚀深度历史计算公式,分析了脉冲宽度对计算准确度的影响。用该方法计算了脉宽为20 ns,波长为1.06μm,峰值强度为500 MW/cm2的脉冲激光烧蚀铝靶过程中光斑中心靶面烧蚀深度的历史,计算结果与文献符合良好。激光脉宽越长,该计算方法越有效。

In order to avoid the complicated physical problems involved in the intense pulsed laser ablation,a method for calculating the depth history of laser ablation using the disciplines of evaporation and condensation is presented.With the histories of pressure and temperature of the vapor at the target surface,the formulas for calculating the history of ablation depth are given.The history of ablation depth at the spot center irradiated by the laser pulse at 1.06 μm with pulse duration of 20 ns and peak intensity of 500 MW/cm2 is calculated.The calculation result is highly consistent with the results in literature.The longer the laser pulse is,the more validity the result has.