空间遥感应用的光学薄膜的偏振特性调控及其性能退化机理研究

The polarization characteristic of new generation of space remote sensing instruments is important in the aspect of quantitative and precise remote sensing information inversion. Based on an original optical monitoring method and atomic layer deposition technology, we propose a new scheme for the development of low polarization sensitive optical films for use in space remote sensing systems. The research goal is to verify an efficient optical monitoring method based on the trigonometric function model, elucidate the analytical design principle of polarization control film and the corresponding error compensation mechanism, and reveal the regulation mechanism of refractive index, crystallization, and defects of the atomic layer deposition film, and finally obtain high-precision polarization characteristics control and performance maintenance. Theoretically, we will study the design method of polarization control film, analyze film structure and key layers distribution, and develop optical monitoring strategies and compensation mechanisms. Experimentally, we will do in-depth study of optical monitoring based on trigonometric function model to improve the precision of film coating, analyze the impact of different shooting and compensation methods on the yield rate. The effects of substrate temperature, vacuum atmosphere of atomic layer deposition process on the layer crystallization, defects, and other characteristics will be studied to solve some basic scientific problems about the regulation mechanism of optical properties and environmental tolerability of film. The results of this study will provide scientific and technical support for the high-precision fabrication of the core and key polarization control films for key equipments.

偏振特性是新一代空间遥感仪器的重要指标，在量化高精度的遥感信息反演方面非常重要。本项目基于一种原创的光学监控方法以及原子层沉积技术，提出应用于空间遥感系统的低偏振灵敏度光学薄膜研制新方案。研究目标在于验证一种基于三角函数模型的简易光学监控方法，阐明偏振薄膜的解析设计原理以及相应的误差补偿机制，揭示原子层沉积膜层的折射率、结晶、缺陷等特性的调控机理，以实现高精度的偏振特性调控和性能保持。理论上研究偏振调控薄膜的设计方法，分析膜系与关键膜层分布，研究光学监控策略及补偿机制。实验上深入研究基于三角函数模型的光学监控提高薄膜研制精度的方法，分析不同判停及补偿机制对良品率的影响；研究基底温度、真空氛围等如何控制原子层沉积膜层的结晶、缺陷等特性，进而影响光学特性和环境耐受性等基础科学问题。研究结果可以为重大装备的核心关键的偏振薄膜的高精度研制生产建立科学基础，提供技术保障。

偏振特性是新一代空间遥感仪器的重要指标，在量化高精度的遥感信息反演方面非常重要。围绕着空间遥感载荷特别是海洋水色遥感仪器对低偏振灵敏度光学薄膜的需求，开发了基于测量新机理的光学薄膜高精度监控技术、应用了原子层沉积技术实现了光学薄膜的高精度的偏振特性调控和性能保持，为最终实现空间遥感载荷的低偏振灵敏度控制目标做出了重要贡献。首先通过理论推导建立了快速反演薄膜厚度的光学监控理论依据，并在国产镀膜机上进行了光学监控系统的改造及监控验证。采用该系统研制了多个带通滤光片，针对滤光片在光线倾斜的应用，获得了滤光膜偏振灵敏度随入射角度的变化关系，用于指导遥感仪器的后光学光路设计。针对诱导透射分色膜，针对敏感膜层进行了设计方法与光学监控策略的创新，成功研制出了偏振灵敏度小于1%的诱导透射分色膜。其次，基于原子层沉积技术的独特优势，设计了一套大尺寸三维基体全表面镀膜反应腔体，实现了对大尺寸自由曲面玻璃基体的全表面均匀镀膜，在国内空间遥感应用中首次具备了大曲率同心透镜的均匀镀膜技术。在银、铜金属膜上通过原子层沉积生长致密保护膜层，实现了金属膜耐500度高温及抗等离子体氧腐蚀的保护性能验证，提升了薄膜的空间遥感应用可靠性。利用原子层沉积纳米叠层实现了对膜层折射率和厚度的双重控制，提高了薄膜器件偏振调控能力。项目的研究结果提升了高精度偏振调控光学薄膜的自主研发能力，满足航天遥感载荷、精密光学仪器等重大装备的自主研发需求。