宽温度范围对变形镜工作性能的影响研究

发布时间：2017-12-31 15:15

本文关键词：宽温度范围对变形镜工作性能的影响研究　出处：《中国科学院光电技术研究所》2017年博士论文　论文类型：学位论文

【摘要】：由于传统自适应光学系统都是安装在望远镜下面的库德房内,所以来自星体的光线要经过一系列的反射镜才能入射到库德房内,这样就会增加系统的复杂性并且使得接受到的光线变暗。用自适应光学系统代替部分反射镜,可以减小系统的复杂性,提高成像光斑的亮度。这时,自适应光学系统的性能会受到环境温度的影响,特别是变形镜的像差校正能力。由于望远镜一般在晚上工作,所以自适应光学系统的工作温度随四季环境变化较大,其最低温度为-10℃,最高温度为20℃。自适应光学系统的光学仪器一般是在室温环境下工作的,所以低温环境下的性能有待研究,特别是作为自适应光学系统核心器件的变形镜。低温变形镜的研究势在必行。简单介绍了自适应光学、低温自适应光学系统和变形镜,分析了目前国内外低温变形镜的研究现状,发现影响低温变形镜性能的两个主要因素是低温初始镜面变形和驱动器的低温性能。另外,分析了各个结构低温变形镜的特点,最终选择分立式连续表面变形镜最为研究对象。从理论上分析了分立式连续表面变形镜低温镜面的主要原因:镜面变形是由变形镜驱动器和底座热膨胀系数不匹配引起的变形镜底座弯曲导致的。采用有限元法提取了61单元ULE变形镜的底座变形和镜面变形,验证了理论分析的正确性。在此基础上,提出了一种解决方案——改进变形镜的结构。从理论上解释了改进结构变形镜的工作原理,并通过有限元法计算了61单元改进结构ULE变形镜的底座变形和镜面变形,发现改进结构变形镜的底座变形和镜面变形都得到了有效地削弱。分析了驱动器排布和镜面材料参数对两种结构变形镜低温镜面变形的影响,发现改进结构的变形镜基本不受这些因素影响。计算了ULE变形镜、K4变形镜、改进ULE变形镜和改进K4变形镜的低温镜面变形,为下一步的实验提供了理论依据。由于影响低温变形镜性能的两个因素是低温初始镜面变形和驱动器的低温性能,所以先测量了驱动器的低温性能。实验结果表明压电陶瓷驱动器在20℃至-60℃之间最大变形量基本不变。说明压电陶瓷驱动器在20℃至-60℃之间是可以正常使用的。测量了四个样镜(ULE变形镜、K4变形镜、改进ULE变形镜和改进K4变形镜)在20℃至-20℃之间的镜面面形,实验结果表明两种结构变形镜的低温镜面变形都随着温度的降低而增大;相同温度下,K4变形镜的镜面变形小于ULE变形镜;改进结构的变形镜能够有效地减小变形镜的低温镜面变形,验证了理论研究的正确性。仿真分析并测试了实际使用的两个913单元变形镜(K4变形镜和ULE变形镜)的全口径和中心区域Φ150mm口径内的低温镜面变形。仿真分析与实验结果基本一致,都表明:K4变形镜的低温镜面变形小于ULE变形镜;低温时,二者的镜面变形反向相反。其中,K4变形镜的低温镜面变形较小,不影响变形镜的像差校正能力,满足了自适应光学系统的实际使用要求。
[Abstract]:Because of the traditional adaptive optics system is installed in the telescope below Kurdish room, so the light from stars to go through a series of mirrors to incident to the Kurds inside the room, it will increase the complexity of the system and makes the light receiving part. The mirror is replaced by an adaptive optical system can reduce the system complexity and improve the brightness of imaging spot. Then, the performance of adaptive optical system can be affected by environmental temperature, especially the aberration correction ability. The deformable mirror telescope at work, so the adaptive optics system working temperature environment changes greatly with seasons, the lowest temperature of -10, the highest temperature is 20 degrees centigrade. Optical the instrument of adaptive optics system is generally working at room temperature, so the performance of low temperature environment to be studied, especially as adaptive optics Deformable mirror is the core component in the system. It is imperative to study the low temperature deformation mirror are introduced. Low temperature adaptive optics, adaptive optics and deformable mirror, analyzes the current research status at home and abroad at the mirror and found two main factors affecting the low temperature performance of the low temperature performance of the deformable mirror is the initial surface deformation and drive temperature. In addition, analysis of the characteristics of different structure of cryogenic deformable mirror, the final choice of discrete continuous surface deformable mirror as the research object. The analysis of the main reason of discrete continuous surface deformable mirror mirror temperature theoretically: Mirror deformation is composed of deformable mirror actuator and a thermal expansion coefficient mismatch caused by the deformable mirror base bending causes. Extraction the 61 element deformable mirror ULE base deformation and surface deformation by finite element method, verify the correctness of the theoretical analysis. Based on this, puts forward a The structure of solutions -- improved deformable mirror. Improve the working principle of the deformable mirror is explained from the theory, and through the finite element method to calculate the 61 unit structure improvement of ULE deformable mirror base deformation and surface deformation, found that the improved structure of mirror base deformation and surface deformation can effectively weaken the influence of low temperature mirror. The thermal deformation of the mirror and mirror drive arrangement of material parameters on the structure of two kinds of deformation analysis, found that the improvement of the basic structure of deformable mirror is not affected by these factors. ULE deformable mirror is calculated, K4 deformable mirror, mirror ULE mirror and improve the low temperature deformation of improved K4 deformable mirror deformation, provides a theoretical basis for the next experiment due to two factors. The effects of low temperature and low temperature performance is the performance of the deformable mirror surface deformation and temperature of the initial drive, so the first measurement of low-temperature performance of the actuator. Experimental results show that the piezoelectric ceramic Porcelain drive maximum deformation is basically unchanged between 20 DEG C to -60 DEG C. That piezoelectric ceramic drive between 20 DEG C to -60 DEG C can be used normally. Four kind of mirror measurement (ULE deformable mirror K4 deformable mirror, improved ULE and improved K4 deformable mirror mirror mirror surface) between 20 C to -20 DEG C, the experimental results show that two kinds of low temperature mirror structure deformable mirror deformation and increases with decreasing temperature; under the same temperature, the K4 deformation of mirror deformation less than ULE deformable mirror; low temperature mirror improved deformable mirror structure can effectively reduce the deformation of mirror deformation, verify the correctness of the theoretical research simulation analysis and test. The two unit 913, the actual use of the deformable mirror (K4 deformable mirror and ULE deformable mirror) full aperture and the central area with 150mm diameter inside the low temperature surface deformation. Simulation analysis and experimental results are basically consistent, show that: K4 deformable mirror The mirror deformation at low temperature is smaller than that of ULE deformable mirror. At low temperature, the mirror deformation of the two faces is reversed. The deformation of the K4 deformable mirror at low temperature is smaller, which does not affect the aberration correction ability of the deformable mirror, and satisfies the practical application requirements of the adaptive optics system.

【学位授予单位】：中国科学院光电技术研究所
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O439

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