NSF/DFG Collaboration Brinksmeier/Riemer/Lucca:"Ultra-Precision Machining and Near Surface Damage Evolution in Single Crystal Fluorides for Advanced Optics"

NSF/DFG 合作 Brinksmeier/Riemer/Lucca：“用于先进光学的单晶氟化物的超精密加工和近表面损伤演化”

• 批准号: 387318746
• 负责人: Dr.-Ing. Oltmann Riemer
• 金额: --
• 依托单位: Abteilung Fertigungstechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/387318746?language=en
• 关键词: NSF; DFG; Collaboration; Brinksmeier; Riemer

NSF/DFG Collaboration Brinksmeier/Riemer (Universität Bremen), Lucca (Oklahoma State University); NSF proposal number # 1727244:The research objective of this proposed study is to test the hypothesis that the degradation in optical performance of single crystal calcium fluoride (CaF2), which has been finished by ul-tra-precision machining, is directly related to the nature and extent of the near surface dam-age introduced. Ultra-precision machining experiments based on linear planing with round nose single crystal diamond tools will be used to determine the critical depth of cut to produce a non-fractured surface for a given crystal orientation.Based on these findings, linear planing and face turning experiments will be performed to generate surfaces for which the surface and subsurface state can be evaluated. Channeling Rutherford backscattering spectrometry (channeling RBS), cross-sectional transmission elec-tron microscopy (XTEM) and high resolution transmission electron microscopy (HR-TEM), and x-ray diffraction (XRD) will be used to provide a quantitative characterization of the sub-surface. The optical performance of the surface will then be assessed by measuring trans-missivity using Ultraviolet-Visible (UV-Vis) spectroscopy and birefringence using a polarime-ter. The project is an international collaboration between Oklahoma State University (OSU), the Laboratory for Precision Machining (LFM) at the University of Bremen, Los Alamos Na-tional Laboratory (LANL) and Carl Zeiss Jena GmbH.The mechanisms responsible for the degradation in optical quality caused by the ultra-precision machining of single crystal fluorides, in particular calcium fluoride (CaF2) are not scientifically understood. This lack of understanding is limiting applications where diamond turning, as opposed to polishing, is required, e.g., nanometer precision aspheric or free-form optics. It is expected that this study will contribute to new fundamental understanding of both the nature and extent of subsurface damage introduced into these brittle, optical materials by ultra-precision (single point diamond) machining. It is envisioned that the findings of this work will be applicable to a range of single crystal alkaline earth fluorides which are finding emerg-ing uses in optical applications. The study will establish a quantitative link between spectrally resolved optical performance and subsurface damage. It will determine whether the degrada-tion in optical performance of single crystal calcium fluoride is directly related to the nature and extent of the near surface damage introduced.

NSF/DFG协作Brinksmeier/Riemer(不来梅大学)，Lucca(俄克拉荷马州立大学)；NSF提案编号#1727244：这项拟议研究的研究目的是验证一种假设，即通过超精密加工完成的单晶氟化钙(CaF2)的光学性能退化与引入的近表面损伤的性质和程度直接相关。基于圆头单晶金刚石刀具直线刨削的超精密加工实验将被用来确定在给定的晶体取向下产生未断裂表面的临界切割深度。在此基础上，将进行直线刨削和面车削实验，以产生可以评估表面和亚表面状态的表面。沟道卢瑟福背散射谱、横截面电子显微镜和高分辨电子显微镜以及X射线衍射仪将被用来提供亚表面的定量表征。然后，将通过使用紫外线-可见光(UV-VIS)光谱测量透过率和使用偏振器测量双折射来评估表面的光学性能。该项目是俄克拉荷马州立大学(OSU)、不来梅大学精密加工实验室(LFM)、洛斯阿拉莫斯国家实验室(LANL)和卡尔·蔡司·耶纳有限公司(Carl Zeiss Jena GmbH)的国际合作项目。超精密加工单晶氟化物，特别是氟化钙(CaF2)导致光学质量下降的机制尚不科学。这种认识的缺乏限制了钻石车削而不是抛光的应用，例如纳米精度非球面或自由形状光学。预计这项研究将有助于对超精密(单点钻石)加工这些脆性光学材料的亚表面损伤的性质和程度有新的基本理解。可以预见，这项工作的发现将适用于一系列正在发现在光学应用中出现的单晶碱土氟化物。这项研究将在光谱分辨光学性能和亚表面损伤之间建立定量联系。这将决定单晶氟化钙光学性能的退化是否与引入的近表面损伤的性质和程度直接相关。