Korean Journal of Optics and Photonics (한국광학회지)

Optical Society of Korea (한국광학회)
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Optimization of 30 cm Lightweight Mirror

30 cm 급 반사경 경량화 최적 설계

  • Kim, Bong-Ho (Department of Laser and Optical Information Engineering, Cheongju University) ;
  • Lee, Jong-Ung (Department of Laser and Optical Information Engineering, Cheongju University) ;
  • Moon, Il-Kwon (Center for Space Optics, Korea Research Institute of Standards and Science) ;
  • Yang, Ho-Soon (Center for Space Optics, Korea Research Institute of Standards and Science) ;
  • Kihm, Hag-Yong (Center for Space Optics, Korea Research Institute of Standards and Science) ;
  • Lee, Yun-Woo (Center for Space Optics, Korea Research Institute of Standards and Science)
  • 김봉호 (청주대학교 대학원 레이저광정보공학과) ;
  • 이종웅 (청주대학교 대학원 레이저광정보공학과) ;
  • 문일권 (한국표준과학연구원 우주광학센터) ;
  • 양호순 (한국표준과학연구원 우주광학센터) ;
  • 김학용 (한국표준과학연구원 우주광학센터) ;
  • 이윤우 (한국표준과학연구원 우주광학센터)
  • Received : 2010.08.10
  • Accepted : 2010.09.08
  • Published : 2010.10.25
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Abstract

Optimization of a 30 cm lightweight mirror was proposed with the best optical performance under various loads of gravity and thermal loads with proper boundary conditions. A pattern for a lightweight mirror was generated based on the best optical performance combined with ease of manufacturing for proper design parameters of physical properties of face sheet, back sheet, rib, and web. Evaluation of the optical performances of a telescope mirror was obtained by using the finite element analysis program, NX I-DEAS. Surface errors, individual aberration terms, such as piston, tilts, focus and other aberrations were calculated by using Zernike polynomials. The proposed telescope mirror meets well the opto-mechanical design consideration of RMS surface error less than 16 nm.

30 cm 급 항공용 반사 망원경계에서 외부 환경 및 내부 진동에 의해 발생하는 주 반사경의 광학적인 성능 저하를 최소화하기 위하여 주 반사경의 광기계 설계를 수행 하였다. 플렉셔를 포함한 주 반사경의 해석을 위한 경계조건으로는 광학면의 수직과 수평 방향의 중력에 의한 변형과 온도 변화 ${\pm}1^{\circ}C$에 의한 열 변형을 고려하였다. 반사경의 기계적인 변형은 NX 5 I-DEAS를 사용하여 해석 하였다. 최적화된 경량화 반사경과 플렉셔의 중력에 의한 광학면의 형상 변형은 RMS surface error 16 nm 이하로 초기 설계 목표값을 만족하였다. 온도 변화 ${\pm}1^{\circ}C$에 의한 광학면의 형상 변형과 assembly load에 의한 광학면의 형상 변형은 매우 작은 값으로 주 반사경의 변형에 영향을 주지 않음을 확인하였다.

Keywords

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