Numerical controlled two optical paths CO2 laser die-cutting technology

A CO2 laser die-cutting system, which does not need die board any more, is a new technique for manufac-turing packing box. Two optical paths, the galvanometer scanning system and the flying optical system, are used to satisfy different processing needs. The scanning system is composed of galvanometer scanning mirrors and F-θ lens. And the flying optical system is driven by two servo motors. This paper presents the software and hardware design of the laser die-cutting system, the difference between the two optical paths, as well as the relationship among the cutting speed, thickness of wrapping paper and laser power. The cutting speed and thickness of wrapping paper are linearly increased by the incremental laser power, while the cutting speed is hyperbolically decreased by the incremental thickness of wrapping paper when the laser power is constant. The amount of incision is reduced by 20% and the processing time by 40% when tested by a low power RF CO2 laser die-cutting system using the optimized program. This tech- nique is also used for the reference of other rapid laser processing systems.     

光路可逆原理错了吗？——对几何光学中一个佯谬的分析

光路可逆原理是几何光学中的重要内容，但有时利用光路可逆原理分析问题却可能出现不自洽的情境。通过一个具体实例引入半波损失的概念，对光波的相位进行分析，用波动光学成功解释了几何光学中的一个佯谬，体现了几何光学和波动光学的紧密联系，培养了学生多角度看待问题的科学思维。同时，对于中学物理光学部分的教学，提出了一些建议。