离轴非球面镜是高精度测量和制造装备不可或缺的光学器件。目前其制造技术的难点在于同时实现高效和高形状精度的加工。笔者借助"子母同体"结构设计和超精密车削技术实现高精度离轴非球面镜加工。利用该结构设计,借助非球面车削加工可实现多个离轴非球面的加工,并从加工路径优化设计和补偿加工技术的研究方面,论述了提高面形精度的方法。实验结果表明:离轴非球面镜的面形精度P-V可在200nm之内,粗糙度Ra约为6nm。
The off-axis aspheric mirror is the vital optical device for the high precision measurement and machining system. However,it is still difficult to fabricate it with high form precision rapidly. This paper aims to solve this problem using the same-body structure and ultra-precision turning. The same-body structure can finish several offaxis aspheric mirrors at the same time of aspheric machining. The precision improvement methods are also discussed in the factors of optimal cutting path design and shape compensation. The experimental results prove that the off-axis mirrors with finish surface roughness of 6 nm and form error within 200 nm can be achieved.