KMS of Xinjiang Astronomical Observatory, CAS
| 大口径主镜膜厚均匀性研究与修正挡板设计 | |
| Alternative Title | Novel Correction Mask for Thickness Uniformity Improvement of Coating on Large Aperture Surface |
程敏
| |
| Subtype | 硕士 |
| Thesis Advisor | 孙正文 ; 艾力•伊沙木丁 |
| 2017 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 天文技术与方法 |
| Keyword | 大口径望远镜 非球面 光学薄膜 膜厚均匀性 修正挡板 |
| Abstract | 为提高光学望远镜性能，大口径和非球面光学元件被逐渐应用于现代望远镜光学设计中。光学设计完成后，光学元件镀膜成为实际影响系统性能的重要因素之一，而薄膜厚度空间分布的均匀性是高性能光学薄膜的一个重要研究方向。本文结合新疆天文台南山观测站1米宽视场光学望远镜和ZZS1800-1/G型 箱式真空镀膜机，主要从不同夹具下膜厚均匀性分析和修正挡板设计两个方面 进行了深入的仿真研究。 本文主要完成的工作如下： (1) 总结了大口径主镜光学镀膜的主要实验设备、工艺流程、膜料选择等； 阐明了光学镀膜的基本原理，分析了薄膜膜厚均匀性的主要影响因素及其具体 影响效果，给出了相应的改进方法。 (2) 针对膜厚均匀性分析，提出了一种新型基于点轨迹和法向量的数值积分算法。首先介绍了光学镀膜均匀性理论分析的几何解析式法，指出了该方法的缺陷；其次提出了一种新型的基于点轨迹和法向量的数值积分法，并将该算法应用于平面型周转夹具、球面型周转夹具以及无倾角的平面型行星夹具，证明了该算法简单可靠；最后结合大口径非球面主镜的相关参数，给出了该算法在非球面基底中的应用，并分析了非球面镀膜与球面镀膜的均匀性差异。 (3) 针对修正挡板设计，提出了一种新型圆周分布式挡板设计方法。首先介绍了传统挡板投影法用于修正挡板设计的基本流程，指出目前修正挡板设计存在的问题；理论分析了球面面型挡板在非球面反射镜镀膜中应用的可行性， 提出了一种新型圆周分布式排列的挡板设计方法，并将该方法应用于大口径非 球面主镜镀膜中，证明了该方案有更好的遮挡效果，能达到膜厚均匀性的要求， 并且有更低的加工成本、更高的结构强度、更优的可操作性。 根据以上分析研究，明确了影响大口径光学镀膜均匀性的主要因素，给出了一套新型膜厚均匀性仿真算法和新型修正挡板设计方法，具有操作简单、可 靠性强等优点，为我国天文光学望远镜日后镀膜的均匀性调控提供一定的参考与借鉴。 |
| Other Abstract | To improve the performance of optical telescope, large aperture and aspheric optical components are gradually applied to the modern telescope optical design. After the optical design is completed, the coating of optical components becomes one of the important factors that affect the performance of the system, and the uniformity of the spatial distribution of film thickness is an important research direction for high performance optical films. In this paper, specific to Nanshan One-Meter Wide Field Telescope and ZZS1800-1/G box type vacuum coating machine, the film thickness uniformity is analyzed and the correction mask is designed. The main work of this paper is as follows: (1) The main experimental equipment, process and material selection of large-aperture main-mirror optical coating are summarized. The basic principle of optical coating is clarified, the main influencing factors of film thickness uniformity and its effect are analyzed. The corresponding improvement methods are put forward. (2) For the uniformity analysis of film thickness, novel numerical integration algorithm based on point trajectory and normal vector is proposed. Firstly, the geometric analytic method of the theoretical analysis of the optical coating uniformity is introduced, and the defects of the method are pointed out. Secondly, novel numerical integration method based on point trajectory and normal vector is proposed, and the algorithm is applied to the planar type fixture, the spherical type fixture and the planar planetary fixture without inclination. The algorithm is proved to be simple and reliable. Finally, the application of the algorithm in the aspheric base is given, and the difference of uniformity between aspheric coating and spherical coating was analyzed. (3) For to the design of the correction mask, novel design method of circular distributed masks is proposed. Firstly, the basic process of the traditional mask projection method for correction mask design is introduced. The disadvantages of the traditional method are pointed out. The feasibility of the application of the spherical mask in the aspheric mirror coating is analyzed theoretically. A new type of circular distributed masks design method is introduced, and the method applied to the large aperture aspheric primary mirror coating, proved that the program has a better occlusion effect to achieve the uniformity of film thickness requirements. The result shows that circular distributed masks, with lower processing costs, higher structural strength, and better operability, are very practical and valuable. According to the analysis above, the main factors influencing the uniformity of large aperture optical coating are clarified, and novel algorithm of film thickness uniformity and novel design method of correction mask are given. These solutions have the advantages of simple operation and high reliability, which can provide some reference for the uniformity regulation of the astronomical optical telescope. |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/1710 |
| Collection | 研究生学位论文 射电天文研究室 |
| Affiliation | 中国科学院新疆天文台 |
| Recommended Citation GB/T 7714 | 程敏. 大口径主镜膜厚均匀性研究与修正挡板设计[D]. 北京. 中国科学院大学,2017. |
| Files in This Item: | ||||||
| File Name/Size | DocType | Version | Access | License | ||
| 2017年硕士学位论文-程敏.pdf（2627KB） | 暂不开放 | CC BY-NC-SA | Application Full Text | |||
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