精密光学系统对光学元件的表面频谱误差的分布提出了控制要求,在加工中如何检测和控制光学元件表面的频谱分布成为一个新的问题.利用功率谱密度对频率的定量化描述功能,对检测数据进行样条插值,在同一极坐标系下计算功率谱密度,求取功率谱密度比值信息,分析小磨具技术的加工工具性能、形状及其运动方式对光学元件表面的频率分布影响.指出在加工中合理地改变加工参数可以快速有效地控制元件表面频谱的分布特征.在670 mm大口径非球面镜加工中做了验证.%The precision optical system has increasingly tighter tolerance demand on optics for applications in science and industry. The detection and control of the frequency distribution of optical surface is a problem. Power spectral density (PSD) was used as a measure to characterize the frequency information about optical surface. The wavefront phase measurement data were transformed to the data in the system of polar coordinates by cubic spline interpolation, and the PSD's ratio was calculated. The influence of the tool performance and its motion in computer controlled optical surfacing (CCOS) technique on the frequency distribution was analyzed. It was pointed out that the characteristics of frequency distribution could be efficiently controlled if the machining parameters were selected properly, which was validated by the manufacture process of a 670 mm diameter aspheric mirror.
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