Korean Journal of Optics and Photonics (한국광학회지)

Optical Society of Korea (한국광학회)
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Improvement of the Shannon Approximation to Correct Effects of Mid-spatial Frequency Wavefront Errors of Concentric Ring Structure in MTF Prediction of Optical Systems

광학계의 MTF 예측에서 동심원 구조의 중간 공간 주파수 파면 오차의 영향이 보정된 Shannon 근사식

  • Seong-Ho Bae (Space Metrology Group, Strategic Technology Research Institute, Korea Research Institute of Standards and Science) ;
  • Ho-Soon Yang (Space Metrology Group, Strategic Technology Research Institute, Korea Research Institute of Standards and Science) ;
  • In-Ung Song (Space Metrology Group, Strategic Technology Research Institute, Korea Research Institute of Standards and Science) ;
  • Sang-Won Park (Space Metrology Group, Strategic Technology Research Institute, Korea Research Institute of Standards and Science) ;
  • Hakyong Kihm (Space Metrology Group, Strategic Technology Research Institute, Korea Research Institute of Standards and Science) ;
  • Jong Ung Lee (Department of Laser and Optical Information Engineering, Cheongju University)
  • 배성호 (한국표준과학연구원 전략기술연구소 우주극한측정그룹) ;
  • 양호순 (한국표준과학연구원 전략기술연구소 우주극한측정그룹) ;
  • 송인웅 (한국표준과학연구원 전략기술연구소 우주극한측정그룹) ;
  • 박상원 (한국표준과학연구원 전략기술연구소 우주극한측정그룹) ;
  • 김학용 (한국표준과학연구원 전략기술연구소 우주극한측정그룹) ;
  • 이종웅 (청주대학교 레이저광정보공학과)
  • Received : 2024.08.22
  • Accepted : 2024.09.25
  • Published : 2024.10.25
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Abstract

We investigate the effects of mid-spatial frequency wavefront errors on the modulation transfer function (MTF) of optical imaging systems such as airborne cameras and astronomical telescopes. To reduce the prediction error of the MTF, an improved Shannon approximation is proposed. The Shannon approximation is useful for low-order wavefront errors, but it has limitations in predicting MTF with high-order wavefront errors, especially those caused by mid-spatial frequency errors from the manufacturing process of aspheric optical components. In this study, we analyze the impacts of concentric ring-shaped mid-spatial frequency wavefront errors on the MTF using MATLAB and Code V simulations and propose a method to improve the Shannon approximation, which has a new correction factor (K-factor).

항공용 카메라 및 천체 망원경과 같은 대구경 광학계의 비구면 반사경 제작 중에 발생하는 동심원 구조의 중간 공간 주파수 파면 오차가 변조전달 함수(modulation transfer function, MTF)에 미치는 영향을 분석하고 Shannon 근사식을 개선하여 MTF 예측 오차를 줄이는 방법을 제안하였다. 기존의 Shannon 근사식은 파면 오차의 차수가 낮은 경우 MTF 예측에 유용하지만, 파면 오차의 차수가 높은 경우, 그중에서도 특히 비구면 광학소자의 제작 과정에서 발생하는 중간 공간 주파수의 파면 오차가 있을 경우 MTF 예측에 한계가 있다. 본 연구에서는 Matlab과 Code V 시뮬레이션을 통해 동심원 구조의 중간 공간 주파수 파면 오차가 MTF에 미치는 영향을 분석하고, 새로운 보정 상수(K-factor)를 가지도록 Shannon 근사식을 개선하는 방안을 제안하였다.

Keywords

Acknowledgement

본 논문은 한국표준과학연구원의 기관고유사업(3-1-05 첨단 대구경 광학측정장비 개발)의 지원을 받아 작성되었다.

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