用于校正大视场共轴光学系统畸变的自由曲面设计方法  

Freeform surface design method for correcting distortion of large-field-of-view coaxial optical systems

作　　者：丁岩 张乃文[1,2] 杨超 薛常喜 DING Yan;ZHANG Naiwen;YANG Chao;XUE Changxi(School of Optoelectronic Engineering,Changchun University of Science and Technology,Changchun 130022,China;Key Laboratory of Advanced Optical System Design and Manufacturing Technology of Universities of Jilin Province,Changchun University of Science and Technology,Changchun 130022,China)

机构地区：[1]长春理工大学光电工程学院,吉林长春130022 [2]长春理工大学先进光学设计与制造技术吉林省高校重点实验室,吉林长春130022

出　　处：《红外与激光工程》2024年第6期106-114,共9页Infrared and Laser Engineering

基　　金：吉林省自然科学基金项目(20220101124JC)。

摘　　要：大视场光学系统的畸变往往较为严重,畸变会导致图像的扭曲和变形,为了解决这个问题,提出了一种利用自由曲面校正大视场共轴光学系统畸变的设计方法,应用该方法可以在优化后期提升光学系统的指标。基于逐点法、矢量折射定律通过光线追迹的方式,根据原有光学系统的出瞳位置和畸变情况,利用自由曲面对各视场主光线进行偏折,进而对畸变进行校正。给出了设计实例,分别拟合出了自由曲面和非球面。对比结果显示,相比于原系统,自由曲面的加入导致TV畸变从–6.3355%下降到0.0002%,相对照度从65.5%下降为50%,调制传递函数从0.54提高到0.64,蒙特卡洛分析90%概率调制传递函数从0.574提高到0.589。相比于相同位置的非球面,自由曲面对系统的畸变校正能力更强,降低了0.2109%,调制传递函数提升了0.06,并且更具有减小系统切向和矢向之间发散的优势,相对照度降低了0.2%,蒙特卡洛分析结果提升了0.002。证明了自由曲面设计方法对大视场共轴光学系统的畸变有着明显的校正作用,体现了自由曲面在大视场共轴光学系统中有着潜在的重要研究和应用价值。Objective With the continuous advancement of optical design and optical manufacturing technology,the performance of optical systems has also been significantly improved.The increase in the field of view is particularly noticeable.However,an increase in the field of view can lead to an increase in the problem of distortion.It is often difficult to correct distortion at the late stage of optical design using optical design software,so it is necessary to study the correction of distortion in optical systems with large fields of view.Freeform surfaces can be used to correct distortion in optical systems due to their large degree of freedom,but current correction methods often utilize aspherical surfaces converted to freeform surfaces,which are weak,cannot correct every field of view,and have uncontrollable surface shapes.Therefore,it is necessary to develop a freeform surface design method for correcting distortion in large-field-of-view coaxial optical systems to minimize the problems of the above design methods.Methods A freeform lens is designed on the premise of the original system,which is inserted into the original optical system as a subsequently added field lens,and optimized as the initial structure for the next step to ultimately achieve the purpose of correcting distortion.Firstly,we analyze the indexes of the original system,and extract the pupil position and image plane information as the starting and ending points.Then the main ray of each field of view after pupil exit is deflected by ray tracing(Fig.3),and the deflection is based on the law of vector refraction(Fig.4).Then the feature data points are calculated based on the point-by-point construction method(Fig.5),and since this process is carried out in a two-dimensional coordinate system,a coordinate transformation scheme is given.Finally,based on the three-dimensional coordinate points,the data are fitted based on XY polynomial freeform surfaces,which in turn gives the freeform coefficients.Results and Discussions Based on the above design methodo

关 键 词：光学设计 自由曲面设计 光线追迹 畸变 大视场 共轴光学系统 

分 类 号：O435[机械工程—光学工程]