摘要由于毫秒激光打孔在实际应用中凸显出它巨大的作用，所以研究毫秒激光打孔中小孔对入射激光的吸收情况有着重要的意义。本课题为了研究小孔对毫秒激光的吸收率，采用3mm厚铝板作为实验材料，根据光电二极管可以将光强转换为电压的原理测吸收率。通过研磨得到小孔纵截面。然后依据小孔纵截面实际形状建立小孔模型，依据光线追迹法计算得到小孔对入射光的吸收率。结果表明，孔面直径随着激光能量的增加而增加，吸收率随着激光能量的增加而减小，实验所测的吸收率与计算结果基本一致。68271

毕业论文关键词  毫秒激光打孔；光线追迹法；吸收率

Title Millisecond laser drilling of holes for the absorption of the incident laser

Abstract

Because the millisecond laser drilling highlights its important role in the practical application, it is significant to study millisecond laser drilling of holes for the absorption of the incident laser. The topic uses the aluminum of three millimeter thick as the experiment materials for the absorption of the incident laser, being based on the principle that photoelectric can convert light intensity to the voltage. The longitudinal and cross section of the holes can be obtained by grinding. Then the holes model is built according to the actual shape of the longitudinal and cross section of the holes and the absorption of the holes to the incident laser is calculated according to the ray tracing method. The result show that hole diameter increases with the increase of laser energy,   the absorption decreases with the increase of laser energy and the absorption measured in the experiment is similar with the absorption calculated from holes model. 

Keywords：Millisecond laser drilling; Ray tracing method; Absorption 

目录

1.引言 2

2 研究现状 2

3 激光与材料作用的理论基础 4

3.1 激光加工的四个过程 4

3.2吸收率 6

3.3激光与材料作用的数学分析 7

3.4光线追迹法 7

4. 毫秒激光打孔中小孔对入射光吸收实验 10

4.1实验原理 10

4.2实验方案 12

4.2.1 打孔前的准备 12

4.2.2激光打孔 12

4.2.3测吸收率 12

4.3实验结果与分析 13

4.3.1形貌图 13

4.3.2光斑大小的测定 14

4.3.3孔面直径与激光能量的关系 15

4.3.4小孔吸收率与激光能量的关系 15

5.吸收率计算 16

5.1模型计算 16

5.2结果分析 16

6.结论 21

致谢 22

参考文献 23

1.引言

21世纪人类己经进入了光电时代，激光技术己经被广泛地应用于科学研究，军事，工业，甚至是日常生活中，并对人类生产活动和生活的改变有着非同凡响的意义。而激光加工技术是激光技术在工业中的主要应用，它加速了对传统加工业的改造，提供了现代工业加工技术的新手段，对工业发展影响很大。