Experimental study on double-pulse laser ablation of steel upon multiple parallel-polarized ultrashort-pulse irradiations
Experimental study on double-pulse laser ablation of steel upon multiple parallel-polarized ultrashort-pulse irradiations
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DOI：
10.1007/s00339-016-0169-6
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发表时间：
2016-06
期刊：
影响因子：
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通讯作者：
J. Schille;L. Schneider;S. Kraft;L. Hartwig;U. Loeschner
中科院分区：
文献类型：
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作者：
J. Schille;L. Schneider;S. Kraft;L. Hartwig;U. Loeschner
本文对双脉冲激光加工进行了实验研究，旨在探索超短脉冲激光对烧蚀效率和质量的影响。为此，序列的50个双脉冲的不同的能量和脉冲间的延迟，调整之间的400 fs和18 ns的激光束分成两个不同长度的光路，被照射到工业级不锈钢。测量产生的凹坑的深度和体积，以评估烧蚀过程的效率;通过SEM显微照片分析凹坑质量。所获得的结果进行了比较与50个单脉冲和能量等于双脉冲序列产生的陨石坑。结果表明，双脉冲处理的烧蚀效率不能超过最佳注量单脉冲的烧蚀效率，但当脉冲间延迟在10 ~ 18 ns范围内时，烧蚀坑表面更加光滑。此外，还研究了双脉冲的脉宽和脉冲间能量分布对烧蚀的影响。对于很短的脉冲间延迟，没有发现双脉冲内的能量变化对去除率的显着影响，表明双脉冲作为一个大的单脉冲的能量相等。此外，当使用飞秒脉冲而不是皮秒脉冲进行双脉冲处理时，实现了更高的去除效率。
In this paper, double-pulse laser processing is experimentally studied with the aim to explore the influence of ultrashort pulses with very short time intervals on ablation efficiency and quality. For this, sequences of 50 double pulses of varied energy and inter-pulse delay, as adjusted between 400 fs and 18 ns by splitting the laser beam into two optical paths of different length, were irradiated to technical-grade stainless steel. The depth and the volume of the craters produced were measured in order to evaluate the efficiency of the ablation process; the crater quality was analyzed by SEM micrographs. The results obtained were compared with craters produced with sequences of 50 single pulses and energies equal to the double pulse. It is demonstrated that double-pulse processing cannot exceed the ablation efficiency of single pulses of optimal fluence, but the ablation crater surface formed smoother if inter-pulse delay was in the range between 10 ns and 18 ns. In addition, the influence of pulse duration and energy distribution between the individual pulses of the double pulse on ablation was studied. For very short inter-pulse delay, no significant effect of energy variation within the double pulse on removal rate was found, indicating that the double pulse acts as a big single pulse of equal energy. Further, the higher removal efficiency was achieved when double-pulse processing using femtosecond pulses instead of picosecond pulses.