一种采用双球面反射补偿检测高次非球面的研究

Research on Detection of High-Order Aspheric Surfaces Using Double Spherical Reflection Compensation

为了完成大口径高次非球面的面形精度检测,提出一种双球面反射式补偿检测系统设计方法。选择与边缘相切的球面为最佳比较球面,拟合出外径为860 mm、中孔为200 mm的高次非球面镜的非球面梯度与法线像差。基于三级像差理论推导补偿检测系统公式,计算出初始参数分析补偿效果并改进优化得到最终结构。经光学软件仿真模拟系统波前差均方根(RMS)小于1/90λ,经过公差分析,98%结果波前差RMS小于1/40λ,满足实际检测要求。该方法能够解决待检高次非球面镜无法检测的难题。

This study proposed a design method for a double spherical reflection compensation detection system to detect the surface accuracy of a large aperture high-order aspheric surface.A spherical surface tangent to the edge as the bestcompared sphere was selected.The aspheric gradient and normal aberration of the high-order aspherical mirror was also fitted with an outer diameter of about 860 mm and a middle hole of about 200 mm.The formula of the compensation detection system was derived using the three-stage aberration theory,and was utilized to calculate the initial parameters,analyze the compensation effect,and improve and optimize the final structure.The wavefront root mean square of the system was less than 1/90λby optical software simulation,and 98%tolerance analysis results revealed that the wavefront is less than 1/40λ,which meets the actual detection requirements.This method can solve the problem of inability to detect high-order aspherical mirrors to be inspected.