AI 中文总结
本文针对CubeSat推扫式高光谱成像有效载荷，设计了一款新型近衍射极限的F/3、焦距100mm的VSWIR单片折反式透镜，通过将焦平面与基底后表面重合解决了狭缝对准难题，具备集成、热稳定等优势。
AI 中文摘要
单片折反式透镜已成为一类新型紧凑型长焦距透镜，由单一熔融石英基底制成，其环形区域具有不同的光学参数，这类系统可在基底内部折叠光路，实现长有效焦距的同时，光路长度仅为折射式等效透镜的一小部分。单片结构和低热膨胀系数使其具备固有的无热性能，能在纳米卫星发射及轨道运行的热载荷与振动载荷下保持光学对准。尽管具备这些优势，但单片折反式透镜的商用产品有限，且尚未发表针对该透镜类别的综合光学设计文献综述。本文调研了单片折反式设计的变体，包括施密特-卡塞格林衍生型、环形折叠型及梯度折射率构型。基于该设计空间，本文还提出了一种为CubeSat推扫式高光谱地球成像有效载荷优化的新型单片折反式物镜。推扫式高光谱成像仪需要在物镜焦平面处设置精准的入射狭缝，而在发射冲击与热循环下保持狭缝至焦平面的对准是一项重大的光学机械挑战。所提出的设计将焦平面与基底后表面重合，使狭缝可通过光刻直接蚀刻在该表面上。该方法消除了狭缝至物镜的对准自由度，为推扫式成像生成了集成、机械坚固且热稳定的物镜-狭缝模块。本文呈现了一款近衍射极限的F/3、焦距100mm的VSWIR单片折反式透镜的完整光学设计，评估了成像性能，并讨论了初步制造与公差考量。
英文摘要
Monolithic catadioptric lenses have emerged as a novel class of compact long-focal-length lenses. Fabricated from a single fused silica substrate with distinct optical prescriptions across annular zones, these systems fold the optical path within the substrate, achieving long effective focal lengths at a fraction of the track length of refractive equivalents. The monolithic architecture and low coefficient of thermal expansion provide inherent athermal performance and preserve optical alignment under the thermal and vibrational loads of nanosatellite launch and orbital operation. Despite these advantages, commercial offerings of monolithic catadioptric lenses are limited and no comprehensive optical design literature review has been published for this lens class. We survey of monolithic catadioptric design variants, including Schmidt-Cassegrain-derived, annular folded, and gradient-index configurations. Building on this design space, we also present a novel monolithic catadioptric objective lens optimized for a CubeSat pushbroom hyperspectral Earth imaging payload. Pushbroom hyperspectral imagers require a precision entrance slit at the focal plane of the objective lens, and maintaining slit-to-focal-plane alignment under launch shock and thermal cycling is a significant optomechanical challenge. The proposed design places the focal plane coincident with the back surface of the substrate, enabling the slit to be lithographically etched directly onto that surface. This approach eliminates the slit-to-objective alignment degree of freedom, yielding an integrated, mechanically robust, and thermally stable objective-slit module for pushbroom imaging. We present the completed optical design of a near-diffraction-limited F/3 f=100mm VSWIR monolithic catadioptric lens, assess imaging performance, and discuss preliminary fabrication and tolerancing considerations.
