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合作Brinksmeier/Riemer （Universität不来梅），卢卡（俄克拉荷马州立大学）；NSF提案号# 1727244：本研究的研究目的是验证单晶氟化钙（CaF2）经超精密加工后的光学性能下降与引入的近表面损伤的性质和程度直接相关的假设。利用圆头单晶金刚石刀具进行直线刨削的超精密加工实验，确定在给定晶体取向下产生非断裂表面的临界切削深度。基于这些发现，将进行线性刨削和面车削实验，以生成可以评估表面和亚表面状态的表面。通道卢瑟福后向散射光谱（Channeling RBS）、横断面透射电子显微镜（XTEM）和高分辨率透射电子显微镜（HR-TEM）以及x射线衍射（XRD）将用于提供亚表面的定量表征。然后，将通过使用紫外-可见（UV-Vis）光谱测量透射率和使用偏振光仪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）和卡尔蔡司耶拿有限公司之间的国际合作项目。单晶氟化物，特别是氟化钙（CaF2）的超精密加工导致光学质量下降的机理尚不清楚。这种理解的缺乏限制了需要金刚石车削而不是抛光的应用，例如，纳米精度的非球面或自由曲面光学。预计这项研究将有助于对超精密（单点金刚石）加工引入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认识。预计这项工作的结果将适用于一系列单晶碱土氟化物，这些氟化物正在光学应用中发现新的用途。该研究将建立光谱分辨光学性能和亚表面损伤之间的定量联系。这将决定单晶氟化钙光学性能的下降是否与引入的近表面损伤的性质和程度直接相关。