The Bulletin of The Korean Astronomical Society (천문학회보)
- Volume 42 Issue 2
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- Pages.88.1-88.1
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- 2017
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- 1226-2692(pISSN)
Design of Linear Astigmatism Free Three Mirror System (LAF-TMS) for Sky Monitoring Programs
- Park, Woojin (School of Space Research, Kyung Hee University) ;
- Pak, Soojong (School of Space Research, Kyung Hee University) ;
- Chang, Seunghyuk (Center for Integrated Smart Sensors, Korea Advanced Institute of Science and Technology (KAIST)) ;
- Kim, Sanghyuk (Optical Astronomical Technology Group, Korea Astronomy and Space Science) ;
- Kim, Dae Wook (College of Optical Sciences, University of Arizona) ;
- Lee, Hanshin (McDonald Observatory, Univ. of Texas at Austin) ;
- Lee, Kwangjo (Department of Applied Physics, Kyung Hee University)
- Published : 2017.10.10
Abstract
We report a novel design of the "linear astigmatism-free" three mirror system (LAF-TMS). In general, the linear astigmatism is one of the most dominant aberration degrading image qualities in common off-axis systems. The proposed LAF-TMS is based on a confocal off-axis three mirror system, where higher order aberrations are minimized via our numerical optimization. The system comprises three pieces of aluminum-alloy freeform mirrors that are feasible to be fabricated with current single-point diamond turning (SPDT) machining technology. The surface figures, dimensions, and positions of mirrors are carefully optimized for a LAF performance. For higher precision-positioning mechanism, we also included alignment parts: shims (for tilting) and L-brackets (for decentering). Any possible mechanical deformation due to assembly process as well as 1-G gravity, and its influence on optical performances of the system are investigated via the finite element (FE) analysis. The LAF-TMS has low f-number and a wide field of view, which is promising for sky monitoring programs such as supernova surveys.
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