衍射光学元件加工中的对心研究

Research on the alignment of the diffractive element axes with the mask center

为了解决平凸折衍混合透镜套刻加工中的对准问题,本文设计了一套进行套刻对准的实验路径。以机械轴为参考基准,使掩模板的环带中心和器件球面的对称轴分别与之对准,最终实现套刻过程中掩模板和器件对称轴的对准。最后根据加工实际情况进行了计算,对于口径是92 mm的衍射元件,得到的对准误差为2.125μm,能够满足系统的要求。采用计算机等辅助手段,可实现亚微米量级的对准精度。

The problem of aligning in the fabrication of diffractive element with a spherical surface is hard to solve.In this paper,we propose a new method of experiment to align the diffractive(element's) axes with the center of mask in the fabrication.In the method,both the axis of the element and the center of the mask can be aligned to the mechanical axes of a laser writing machine.By the analysis of a diffractive element with diameter of 92 mm,the precision could reach 2.125 μm and satisfy the demand of the fabrication.And it is concluded that the precision could be a few sub-micron with the help of computer.