Abstract
Today, CVD SiC mirrors are readily available in the market. However, it is well known to the community that the key surface fabrication processes and, in particular, the material removal characteristics of the CVD SiC mirror surface varies sensitively depending on the shop floor polishing and figuring variables. We investigated the material removal characteristics of CVD SiC mirror surfaces using a new and patented polishing tool called orthogonal velocity tool (OVT) that employs two orthogonal velocity fields generated simultaneously during polishing and figuring machine runs. We built an in-house OVT machine and its operating principle allows for generation of pseudo Gaussian shapes of material removal from the target surface. The shapes are very similar to the tool influence functions (TIFs) of other polishing machine such as IRP series polishing machines from Zeeko. Using two CVD SiC mirrors of 150 mm in diameter and flat surface, we ran trial material removal experiments over the machine run parameter ranges from 12.901 to 25.867 psi in pressure, 0.086 m/sec to 0.147 m/sec in tool linear velocity, and 5 to 15 sec in dwell time. An in-house developed data analysis program was used to obtain a number of Gaussian shaped TIFs and the resulting material removal coefficient varies from 3.35 to 9.46 um/psi hour m/sec with the mean value to 5.90 ± 1.26(standard deviation). We report the technical details of the new OVT machine, of the data analysis program, of the experiments and the results together with the implications to the future development of the OVT machine and process for large CVD SiC mirror surfaces.
Original language | English |
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Title of host publication | Optical Manufacturing and Testing XI |
Editors | Ray Williamson, Oliver W. Fahnle, Dae Wook Kim |
Publisher | SPIE |
ISBN (Electronic) | 9781628417418 |
DOIs | |
Publication status | Published - 2015 |
Event | Optical Manufacturing and Testing XI - San Diego, United States Duration: 2015 Aug 9 → 2015 Aug 11 |
Publication series
Name | Proceedings of SPIE - The International Society for Optical Engineering |
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Volume | 9575 |
ISSN (Print) | 0277-786X |
ISSN (Electronic) | 1996-756X |
Other
Other | Optical Manufacturing and Testing XI |
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Country/Territory | United States |
City | San Diego |
Period | 15/8/9 → 15/8/11 |
Bibliographical note
Publisher Copyright:© 2015 SPIE.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering