组合激光对单晶硅热作用的数值分析

摘要

In order to improve coupling efficiency of laser energy of monocrystalline silicon in laser processing, a short laser pulse and a long laser pulse were used to form a combined pulse to irradiate the monocrystalline silicon.The process was simulated by using COMSOL software.The influences of the delay time of combination laser and the laser energy density of long pulse on the process effect were obtained.The effect was compared with that of individual action millisecond laser under the equal total energy.The measured damage morphologies of monocrystalline silicon irradiated by lasers with different power intensities were in agreement with the trend of numerical results.The results show that the combined laser can improve the coupling efficiency of laser.The different delay time would affect the process effect of the combined laser.The optimum delay time is 0.1ms.When the ratio of the millisecond laser energy density in the combined laser is relatively low, the effect is obvious.With the increase of the ratio of the millisecond laser energy density, the enhancement of the effect is relatively slow.The research results can provide theoretical and experimental basis for the application of combined laser.%为了提高激光加工中单晶硅材料对激光能量的耦合效率,采用一个短脉冲激光和一个长脉冲激光形成组合激光辐照单晶硅,使用COMSOL软件对该过程进行模拟,得到了组合激光长短脉冲间的延迟时间和长脉冲激光能量密度的变化对作用效果的影响,并与总能量相等的毫秒激光单独作用的效果进行比较;实验测量得到的不同能量密度的激光作用单晶硅后损伤形貌,与数值计算结果的趋势吻合.结果表明,组合激光能提高材料对激光的耦合效率;不同的延迟时间会影响组合激光的作用效果,最佳延迟时间为0.1ms;组合激光中毫秒激光能量密度占比较低时,作用效能较明显,随着毫秒激光能量密度占比的提高,对作用效果的提升相对变缓.该研究结果可以为组合激光的应用提供理论和实验依据.