Mirror Tech 2016 2016. 11. 01. Jeong-Yeol Han, Myung Cho, Gary Poczulp, Dong-Kyun Kim, Hyoung Kwon Lee, Jinho Kim, Hyunju Seo, Sehyun Seong, Sug-Whan Kim, Min-Gab Gog, Jong-Su Jeon, Jihun Kim, Young-Soo Kim, Ukwon Nam, Gun Hee Kim, Sang Won Hyun, Minwoo Jeon Korea Astronomy and Space Science Institute (KASI) National Optical Astronomy Observatory (NOAO) Green Optics Co., Ltd., YoonSeul Co., Ltd, Yonsei University Korea Basic Science Institute (KBSI)
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Mirror Tech 2016
2016. 11. 01.
Jeong-Yeol Han, Myung Cho, Gary Poczulp, Dong-Kyun Kim, Hyoung Kwon Lee, Jinho Kim, Hyunju Seo, Sehyun Seong, Sug-Whan Kim, Min-Gab Gog, Jong-Su Jeon,
Jihun Kim, Young-Soo Kim, Ukwon Nam, Gun Hee Kim, Sang Won Hyun, Minwoo Jeon
Korea Astronomy and Space Science Institute (KASI)National Optical Astronomy Observatory (NOAO)
Green Optics Co., Ltd., YoonSeul Co., Ltd, Yonsei UniversityKorea Basic Science Institute (KBSI)
Contents
Introduction
Preparation of thermal test setup
TIF analysis
Conclusion
INTRODUCTION
1. Collaboration plan overview
• Collaboration partners: NOAO, KASI, GO
• Objectives• Develop polishing and testing procedures for SiC lightweight blanks
• For 300 mm flat blanks• Polishable surfaces (Si CVD, or SiC CVD over-coated)
• Test of optical and mechanical characteristics• Optical surface WFE maps• Environmental tests (Thermal tests)
200 Ave. S #3 Ave. S #4 Ave. O-rib Ave. O-no_rib Ave. W-rib Ave. W-no_rib Ave. D Ave. SSG Ave. POCO Ave. Coorstek
Dep
th (n
m)
Removal coefficient (um/psi hr m/sec)
Average TIFs of SiC for both Korea and USA
- P corp. (US): most polishable material (due to Si overcoated, probably)
- W corp. (Korean): most difficult material to polish out- S corp. (US): No linear trends- Similar TIF characteristics: C corp. & O, S1#3 // S1#4 & D- S1 corp (Korean): Different characteristics à Capability to manufacture various SiC- TIF of both rib and no rib surfaces (but the difference represents not quite different)
- Rib > No rib: O corp.- No rib > Rib: W corp.
C corp.P corp.S corp.
S1 corp. #3S1 corp. #4
MARI concept can be used to characterize various SiC materials
v It would be great to have a chance to get additional meaningful data during environmental testing at 2017 (plan)§ Obtain a WFE pattern with different temperature
à Fixed location of interferometer
v Preparation of Phase II planning by NOAO§ Period: 2016~2018 (3 years)§ Size: 500 mm in diameter§ Shapes: Off-axis aspheric, Convex aspheric, Concave aspheric§ Scope: Development of both polishing and material process