Lu Qi, Ding Yifan, Wang Wei, Liu Shijie, Xu Min
Appl Opt. 2022 Oct 20;61(30):8880-8888. doi: 10.1364/AO.465959.
In general, lenses with different materials can achieve at most (+1) color correction (≥2). A superachromat containing three lenses is designed to achieve five-color correction in the 600-1600 nm waveband, where the maximum chromatic focal shift is controlled within 1/100,000 of the focal length, achieving an almost unprecedented result. Conditions for lens power combination of three thin lenses in contact are first derived based on the Buchdahl dispersion equation; then a metric is introduced to verify the five-color correction, and a correction method is proposed to improve the refractive index fitting accuracy of the Buchdahl model from ∼10 to ∼10. By traversing 197 ecofriendly glass materials in the CDGM glass library iteratively, 113 initial structures are obtained in only 61.75 s, from which the structure with the minimum chromatic focal shift is selected to be optimized with Opticstudio. By setting up required operands, the final structure being within the diffraction limit in a field of view of ±0.05 is obtained within only 6 s, where the maximum longitudinal chromatic aberration is close to the maximum chromatic focal shift. We provide a complete theoretical basis and important guidance for designing broadband superachromats with (+2) color correction using only lenses and the smallest chromatic focal shift, and based on the theories, we have developed a broadband interferometer.
一般来说，不同材料的透镜最多能实现（+1）级色差校正（≥2）。一种包含三个透镜的超消色差透镜被设计用于在600 - 1600纳米波段实现五级色差校正，其中最大色差焦移被控制在焦距的1/100,000以内，取得了几乎史无前例的成果。首先基于布赫达尔色散方程推导了三个薄透镜接触时的透镜光焦度组合条件；然后引入一个度量来验证五级色差校正，并提出一种校正方法将布赫达尔模型的折射率拟合精度从约10提高到约10。通过在CDGM玻璃库中迭代遍历197种环保玻璃材料，仅用61.75秒就获得了113个初始结构，从中选择色差焦移最小的结构用Opticstudio进行优化。通过设置所需的操作数，仅用6秒就在±0.05的视场内获得了在衍射极限内的最终结构，其中最大纵向色差接近最大色差焦移。我们为仅使用透镜设计具有（+2）级色差校正且色差焦移最小的宽带超消色差透镜提供了完整的理论基础和重要指导，并基于这些理论开发了一种宽带干涉仪。
