特大非球面度离轴非球面补偿器结构设计与装调

摘要

针对快焦比特大非球面度离轴非球面反射镜,设计了3片式Offner补偿器.为应对3片式补偿器对中心偏差及镜间隔严格的公差要求,设计了相应的补偿器镜筒结构.该结构使透镜中心倾斜及平移调整相分离,实现补偿器的高精度装调.根据中心偏差测量仪的测量结果,2片补偿镜之间倾斜误差4.4″,平移误差3.5 μm, 镜间隔误差3.8 μm;补偿镜组与场镜之间倾斜误差5.3″,平移误差4.2 μm, 镜间隔误差7.2 μm,满足检测使用要求.利用该补偿器及4D动态干涉仪对精抛光阶段的离轴非球面进行检测,面形结果PVq值达到0.135λ,RMS值达到0.019 5λ,优于设计要求.%Three-lens Offner compensator was designed for off-axis aspheric surface with fast ratio and large asphericity.Because tolerance requirement of centering errors and air gap distances is very severe,corresponding barrel structure of compensator is designed.The structure separates line-centering error adjustment and angle-centering error adjustment, which can achieve high accuracy adjustment of the compensator.According to measuring results of center deviation measuring apparatus, finally angle-centering error between compensating lenses is 4.4″, line-centering error is 3.5 μm, and air gap distance error is 3.8 μm.Angle-centering error between compensating lenses series and field lens is 5.3″,line-centering error is 4.2 μm, and air gap distance error is 7.2 μm, which meet the demand of testing.Off-axis aspherical surface is tested by 4D interferometer and the compensator,PVq value is 0.135λ and RMS value is 0.019 5λ, better than designing requirements.