变斑变焦激光切割光学系统的设计

Design of Variable Spot and Zoom Optical System for Laser Cutting

为了满足不同材料、不同厚度板材加工的需求,设计了一种光斑大小和焦点位置可变的激光切割光学系统,该变斑变焦激光切割光学系统由复合准直镜组、变焦镜组、补偿镜组和聚焦镜组组成;采用在普通光学聚焦系统的准直镜组与聚焦镜组中间放置可调倍率扩束系统,再将准直镜组和可调倍率扩束系统合并成一个复合准直镜组的方案,简化了系统设计;建立了四镜组可变斑变焦光学系统的物理模型,推导了各镜组之间的移动规律,并利用MATLAB软件进行理论验证;在现有切割光学系统的基础上,设计一种变斑变焦激光切割光学系统,并利用软件优化像差。结果表明:通过移动变焦镜组和补偿镜组,得到了放大倍率为1.000～3.750、焦点上下可调范围为-20～+10 mm的焦斑,实现了焦斑大小和焦点位置的精准可调。

To meet the needs of metal processing with different materials and different thicknesses, we design a variable spot and zoom laser cutting optical system which consists of a composite collimating lens group, a zoom lens group, a compensated lens group, and a focusing lens group. We adopt an adjustable magnification expansion beam system in the middle of the collimating lens group and the focusing lens group of the ordinary optical focusing system, and then combine the collimating lens group and the adjustable magnification beam expanding system into a composite collimating lens group to simplify the system. We establish a physical model of the variable spot and zoom optical system with four lenses, derive the geometric locus of zoom group and compensated group. Theory verification is performed with MATLAB software. Based on the existing cutting optical system, we design a variable spot and zoom laser cutting optical system, and optimize the aberrations by using software. The results show that when we move the zoom lens group and the compensated lens group, the magnification is from 1.000 to 3.750, and the focus up and down adjustable range is from-20 mm to +10 mm. The precise adjustment of the focal spot size and focus position is thus realized.