长焦镜头光学系统设计及无热化研究  

Optical System Design and Athermalization of Telephoto Lens

作　　者：张丽芝 陆秋萍 段帆琳 戴幸 乔大勇[1,3] Zhang Lizhi;Lu Qiuping;Duan Fanlin;Dai Xing;Qiao Dayong(MOE Key Laboratory of Micro&Nano Systems for Aerospace,Northwestern Polytechnical University,Xi'an 710072,Shaanai,China;Ningbo Yongcin Optics Co.,Ltd.,Ningbo 315048,Zhejiang,China;Ningbo Institute of Northwestern Polytechnical University,Ningbo 315103,Zhejiang,China)

机构地区：[1]西北工业大学空天微纳系统教育部重点实验室,陕西西安710072 [2]宁波永新光学股份有限公司,浙江宁波315048 [3]西北工业大学宁波研究院,浙江宁波315103

出　　处：《光学学报》2024年第8期219-228,共10页Acta Optica Sinica

基　　金：国家自然科学基金(U21B2035,62074128)。

摘　　要：为满足车载激光雷达接收光学系统在复杂环境实际应用中的温度适应性要求,本文基于一种将长焦镜头与线阵探测器相结合,通过局部图像级成像显著提高激光雷达系统探测分辨率的方案,设计了一款轻小型无热化的四片式全玻璃长焦镜头,研究了其在不同温度下的像面漂移。分析结果表明,所设计的长焦镜头在整个-40~100℃的温度范围内焦移量为0.021 mm,小于焦深0.074 mm,在30 lp/mm处各视场调制传递函数(MTF)均大于0.5,全视场内光斑半径在7μm以下,水平及垂直角分辨率为0.045°(H)×0.045°(V)。此长焦接收光学系统结构简单、成像质量高、环境适应性强,在车载激光雷达领域具有良好的应用前景。Objective The actual working environment of vehicle-mounted LiDAR is complex,including seasonal long-time limit temperature and rapid changes in indoor and outdoor high and low temperatures.These temperature variations possibly change the internal optics and structure of the lens,which results in image plane drift and reduces imaging quality.For telephoto lenses,the image plane drift can be more obvious with the ambient temperature changes.The current passive athermalization design method has the problems of complex structure and large volume caused by multi-layer lens barrels,or the introduction of diffractive elements and aspheric lenses to increase the production cost,and the narrow temperature range of thermal-free,which is difficult to adapt to the practical applications in the complex environment of vehiclemounted LiDAR.Therefore,it is necessary to reduce the image plane temperature drift and improve the environmental adaptability of telephoto lenses with an advanced athermal design method.Methods The telephoto lens which can accurately capture distant targets and magnify the details is integrated with a line array detector to improve the resolution.Meanwhile,based on the fact that the total length of the optical system of the telephoto structure is smaller than the focal length,the volume of the telephoto receiving optical system is compressed to a certain extent to realize the requirements of lightweight miniaturization and high resolution of the vehicle-mounted LiDAR.Aiming at the problem that the telephoto lens is susceptible to temperature,we improve the two-group compensation design method of the passive optical and mechanical athermalization to maximally offset the optical focal length change of the optical parts from the thermal difference brought by thermal expansion and contraction of the structural parts,and to reduce the image plane drift,thus realizing the athermalization of the telephoto lens.Finally,the image plane drift of the asdesigned lens is less than the depth of focus over a wide tempe

关 键 词：车载激光雷达 长焦光学系统 光学设计 无热化 

分 类 号：O439[机械工程—光学工程]