Kashima Shingo, Hazumi Masashi, Imada Hiroaki, Katayama Nobuhiko, Matsumura Tomotake, Sekimoto Yutaro, Sugai Hajime
Appl Opt. 2018 May 20;57(15):4171-4179. doi: 10.1364/AO.57.004171.
A side-fed crossed Dragone telescope provides a wide field of view. This type of telescope is commonly employed in the measurement of cosmic microwave background polarization, which requires an image-space telecentric telescope with a large focal plane over broadband coverage. We report the design of a wide field-of-view crossed Dragone optical system using anamorphic aspherical surfaces with correction terms up to the 10th order. We achieved a Strehl ratio larger than 0.95 over 32×18 square degrees at 150 GHz. This design is an image-space telecentric and fully diffraction-limited system below 400 GHz. We discuss the optical performance in the uniformity of the axially symmetric point-spread function and telecentricity over the field of view. We also address the analysis to evaluate the polarization properties, including the instrumental polarization, extinction rate, and polarization angle rotation. This work is a part of a program to design a compact multi-color wide-field-of-view telescope for LiteBIRD, which is a next-generation cosmic microwave background (CMB) polarization satellite.
侧馈交叉式德拉贡望远镜提供了广阔的视野。这种类型的望远镜通常用于宇宙微波背景极化测量，这需要一个在宽带覆盖范围内具有大焦平面的像方远心望远镜。我们报告了一种使用高达十阶校正项的变形非球面的宽视场交叉式德拉贡光学系统的设计。在150吉赫兹时，我们在32×18平方度的范围内实现了斯特列尔比大于0.95。该设计是一个像方远心且在400吉赫兹以下完全衍射受限的系统。我们讨论了轴对称点扩散函数的均匀性和视场内远心性方面的光学性能。我们还进行了分析以评估偏振特性，包括仪器偏振、消光率和偏振角旋转。这项工作是为LiteBIRD设计一个紧凑的多色宽视场望远镜计划的一部分，LiteBIRD是一颗下一代宇宙微波背景（CMB）极化卫星。
