应用于中短波红外天文观测的空间低温光学系统研究

发布时间：2019-03-28 14:59

【摘要】：红外探测是最重要的遥感手段之一,在军事、气象、资源、环境减灾、天文等各个领域获得了广泛应用。随着技术的发展,人们在红外天文观测、高分辨率红外对地观测、微弱目标探测等多个领域的应用中,对红外遥感仪器提出了更高灵敏度的探测需求。低温光学系统可以充分地降低仪器自身背景,有效地提高红外系统的探测灵敏度,对满足上述应用需求有极大的意义。本文主要结合我国当前的中短波红外天文观测需求和相关技术发展水平,开展针对未来空间应用的红外低温光学系统的设计、装调和低温测试技术研究。论文根据空间红外系统的基本结构特征,对红外系统自身背景辐射进行了分析研究,建立了相应的计算模型。分析了红外天文观测和对地观测对背景辐射控制需求的差异,并结合红外系统信噪比计算模型分析了背景辐射对红外系统探测灵敏度的影响,讨论了抑制背景辐射的方法。论文针对空间多环芳香烃(PAH)巡天探测对红外望远镜的技术要求,开展了大口径低温光学系统的设计研究。采用常温初始设计—低温优化—常温补偿实现的技术路线,从光学结构选型、材料选择、低温参数计算、离焦补偿等方面,对100K温区红外望远镜进行了设计分析。论文开展了适应低温应用的望远镜支撑结构设计研究。采用不同材料组合利用尺寸链计算匹配法进行无热化设计;采用交叉柔性铰链设计实现低温望远镜的消热差支撑结构,利用基于多目标遗传算法优化的响应面法对柔性支撑结构进行优化设计。论文开展了低温光学系统的装调和低温测试技术研究。分别开展了元件、组件和系统级的低温测试研究。首次开展国产碳化硅反射镜的低温应用研究。开展了碳化硅制备工艺和热控工艺对系统低温性能的影响测试研究;仿真分析了温度非均匀性对反射镜面型和系统波像差的影响。论文在上述几个方面的研究成果的基础上,在国内首次完成了100-150K温区Φ300mm大口径低温碳化硅望远镜的研制。装调和低温测试结果表明,望远镜在130K温度下的系统波像差优于133nm,在2μm以上达到衍射极限。这些工作将为未来空间天文望远镜的研究打下比较好的基础。
[Abstract]:Infrared detection is one of the most important remote sensing methods. It has been widely used in many fields such as military, meteorology, resources, environmental disaster reduction, astronomy and so on. With the development of technology, people in infrared astronomical observation, high-resolution infrared earth observation, weak target detection and other fields of application, for infrared remote sensing instruments to put forward higher sensitivity detection requirements. The low temperature optical system can fully reduce the background of the instrument and effectively improve the detection sensitivity of the infrared system, which is of great significance to meet the requirements mentioned above. In this paper, the design of infrared low-temperature optical system for future space applications, assembly and low-temperature testing technology are studied based on the current requirements of medium-and short-wave infrared astronomical observation in China and the development level of related technologies. According to the basic structure characteristics of the space infrared system, the background radiation of the infrared system is analyzed and studied, and the corresponding calculation model is established. The difference between infrared astronomical observation and earth observation for background radiation control is analyzed. The influence of background radiation on the detection sensitivity of infrared system is analyzed by combining the calculation model of signal-to-noise ratio of infrared system, and the methods to restrain background radiation are discussed. Aiming at the technical requirements of infrared telescope for space polycyclic aromatic hydrocarbons (PAH), the design and research of large aperture and low temperature optical system are carried out in this paper. The 100K infrared telescope is designed and analyzed from the aspects of optical structure selection, material selection, low temperature parameter calculation, defocus compensation and so on by using the technical route of initial design at room temperature, optimization at low temperature and compensation at room temperature. In this paper, the design of telescopes supporting structure suitable for cryogenic applications has been carried out. Non-thermal design is carried out by means of dimensional chain calculation matching method with different material combinations. The design of cross flexure hinge is used to realize the anti-heat difference support structure of low temperature telescope. The response surface method based on multi-objective genetic algorithm is used to optimize the design of flexible support structure. In this paper, the research of low-temperature optical system assembly and low-temperature testing technology has been carried out. The low temperature testing of components, components and systems were carried out respectively. The application of domestic silicon carbide mirror at low temperature is studied for the first time. The effects of silicon carbide preparation process and thermal control technology on the low temperature performance of the system are studied, and the effects of non-uniformity of temperature on the reflection mirror type and the system wave aberration are simulated and analyzed. On the basis of the above-mentioned research results, the development of 桅 300mm large aperture low temperature silicon carbide telescope at 150 K is completed for the first time in China. The results of assembly and low temperature measurements show that the wave aberration of the telescope at 130 K is better than 133 nm and the diffraction limit is over 2 渭 m. These work will lay a good foundation for the future research of space astronomical telescopes.
【学位授予单位】：中国科学院大学(中国科学院上海技术物理研究所)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：P111;TN219

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