基于视线标定立体偏折术的离轴非球面面形检测  

Stereo Deflectometry for Measuring Off-Axis Aspherical Surface Based on Vision Ray Model

作　　者：路凯 王瑞阳 李大海[1,2] 葛忍好 郑万兴 Lu Kai;Wang Ruiyang;Li Dahai;Ge Renhao;Zheng Wanxing(College of Electronics and Information Engineering,Sichuan University,Chengdu 610065,Sichuan,China;College of Aeronautics and Astronautics,Sichuan University,Chengdu 610065,Sichuan,China)

机构地区：[1]四川大学电子信息学院,四川成都610065 [2]四川大学空天科学与工程学院,四川成都610065

出　　处：《中国激光》2024年第13期115-123,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(U20A20215,62375190);四川大学基金(2020SCUNG205)。

摘　　要：为实现离轴非球面光学元件面形的准确高效测量,提出一种基于立体偏折术并结合点云匹配数据处理的方法,该方法可用于离轴非球面光学元件结构参数的拟合与面形测量。首先,根据立体偏折术原理获得离轴非球面的点云数据,然后,利用点云数据与离轴非球面理论模型的几何关系,通过非线性最小二乘算法对姿态误差和非球面结构参数进行优化,最后,利用上述的几何关系、姿态误差和优化后的结构参数完成点云数据和理论模型的匹配,进而获得离轴非球面元件面形。为了验证所提方法的可行性,对顶点曲率c=1/678.91 mm^(-1)、离轴量b=100 mm、圆锥系数k=-1、口径为142 mm且有附加面形误差的离轴非球面元件进行了数值模拟,并实验测量了一块离轴非球面光学元件,对其结构参数进行优化后,得到了与干涉仪较为接近的面形测量结果。仿真和实验结果表明了所提方法用于离轴非球面光学元件面形测量时的可行性。Objective In recent years,the demand for improved optical systems has resulted in the utilization of spherical elements,which can correct aberrations and enhance imaging quality.However,the common practice of incorporating additional optical elements for aberration correction increases the volume and weight of optical instruments,thus contradicting the trend toward lightweightness and miniaturization.By contrast,aspherical optical elements with varying curvatures can effectively correct aberrations,improve imaging quality,and satisfy the requirements of lightweightness for optical systems.Consequently,they have broader applications in healthcare,aerospace,astronomy,and high-power lasers.The non-coincidence of the geometric and optical axes in off-axis aspherical elements provides additional degrees of freedom for aberration correction in optical system designs.Whereas this addresses issues such as center obstruction,which can degrade the imaging quality,it increases the difficulty in measuring the surface of the elements.Commonly used methods for measuring the surfaces of off-axis aspherical elements include interferometry and profilometry.Interferometry utilizes changes in the optical-path difference to generate interference fringes,thereby enabling high-precision surface measurements.However,interferometric precision is affected by the environment and typically requires additional compensatory devices for off-axis aspherical-element measurements.Profilometry,which uses a mechanical probe in contact with the surface of an element and a detector to sense changes in the height of the contact point,achieves point-by-point measurements of an element s profile.However,its motion mechanism renders high-precision measurement challenging and contact between the probe and the tested element s surface can cause surface damage.Conventional phase-measuring deflectometry has been widely applied as a nondestructive and efficient technique for measuring the shape of optical-element surfaces.However,obtaining highly accurate co

关 键 词：视线标定 立体偏折术 离轴非球面元件 面形 点云匹配 

分 类 号：O436[机械工程—光学工程]