학술지/매거진
Current Optics and Photonics
Vol. 5, No.6(Dec. 2021)
한국광학회지
Vol. 32, No.6(Dec. 2021)
K-Light
Vol4, No.4(Oct. 2021)
Current Optics and Photonics
Vol. 5, No.6(Dec. 2021)
한국광학회지
Vol. 32, No.6(Dec. 2021)
K-Light
Vol4, No.4(Oct. 2021)
![[Editors Pick] Current Optics and Photonics Vol. 5 no. 6 (2021 December)](https://www.osk.or.kr/upload/posts_thumb/2021/12/1640570143_97566000_1587723648-thumb.png)
[Editors Pick] Current Optics and Photonics Vol. 5 no. 6 (2021 December)
Fourier Modal Method for Optical Dipole Radiation in Photonic Structures
Sungjae Park1ㆍJoonku Hahn2ㆍHwi Kim1*
Current Optics and Photonics Vol. 5 No.6 (2021 December) pp. 597-605
DOI: https://doi.org/10.3807/COPP.2021.5.6.597
Fig. 1 Photonic multiblock structure with an optical-source-embedding block, and the optical field distributions for (a) a dipole with polarization P = (1, 0, 0) and (b) a dipole with polarization P = (0, 0, 1). The thicknesses of block #1, the cathode, block #2, the active block, block #3, and the anode are 70 nm, 8 nm, 31 nm, 38 nm, 157 nm, and 114 nm respectively, and their refractive indices (n + jk) are 1.88, 0.191 + 3.24j, 1.71, 1.84 + 0.00272j, 1.94, and 0.129 + 3.19j, respectively.
Keywords: Fourier modal method, Numerical modeling
OCIS codes: (000.3860) Mathematical methods in physics; (050.1755) Computational electromagnetic methods; (050.1960) Diffraction theory
Abstract
An extended Fourier modal method (FMM) for optical dipole radiation in three-dimensional photonic structures is proposed. The core elements of the proposed FMM are the stable bidirectional scatteringmatrix algorithm for modeling internal optical emission, and a novel optical-dipole-source model that prevents numerical errors induced by the Gibbs phenomenon. Through the proposed scheme, the FMM is extended to model a wide range of source-embedded photonic structures.
![[하이라이트 논문] 한국광학회지 Vol. 32 No.6 (2021 December)](https://www.osk.or.kr/upload/posts_thumb/2021/12/1640570156_52213700_1365535689-thumb.png)
[하이라이트 논문] 한국광학회지 Vol. 32 No.6 (2021 December)
Korsch 망원경의 열분석을 통한 광학계 성능 평가 방법 및 비열화 구조 연구
A Study on the Method of Evaluating Optical-system Performance and an Athermal Structure through Thermal Analysis of the Korsch Telescope
김규호1ㆍ박성우1ㆍ박승한2ㆍ이경묵3ㆍ정미숙1†
한국광학회지 Vol. 32 No.6 (2021 December) pp. 266-275
DOI: https://doi.org/10.3807/KJOP.2021.32.6.266
Fig. 1 The layout of the thermal analysis process.
Keywords: 비열화 설계, 인공위성, 구조체, 망원경, 열분석
OCIS codes: (080.2740) Geometric optical design; (350.4600) Optical engineering
Abstract
본 논문은 Korsch 망원경의 열분석을 통한 광학계 성능 평가 방법 및 비열화 구조를 연구하였다. 비대칭성의 복잡한 구조를 가진 광학계의 경우, 광학 설계 소프트웨어에 열팽창 계수를 적용하여 인공위성 구조를 구현하는데 한계가 있어 온도 변화에 대한 광학계 성능 평가가 이루어지기 어렵다. 이러한 문제점을 해결하기 위해 기계 설계 소프트웨어를 이용하여 온도에 따라 광학계에 영향을 주는 모든 구조체에 길이 변화를 구현하였고, 온도 변화에 대한 광학 부품 사이의 거리 변화량을 정리하였다. 또한 광학 설계 소프트웨어를 이용하여 온도 변화에 대한 광학 부품의 형상 및 두께 변화량을 정리하였다. 두 소프트웨어에서 도출한 모든 변화량을 광학 소프트웨어에 적용하여 광학계의 성능 평가를 진행하 였다. 그 결과 공간 분해능 71.4 cycles/mm에 대한 변조전달함수(MTF)가 9 ℃에서 33 ℃까지의 범위에서 25% 이상 유지되는 것을 확인하였 다. 또한 광학계 성능 변화에 가장 영향을 많이 주는 구조체를 찾아, 영향을 줄이도록 비열화 구조를 도출하여 개선된 구조물을 적용한 광학계의 성능 평가를 진행하였다. 그 결과, 분해능 71.4 cycles/mm에 대한 변조전달함수가 9 ℃에서 33 ℃까지의 범위에서 67% 이상 유지되는 것을 확인하였다.
In this paper, a method for evaluating optical-system performance and an athermal structure through thermal analysis of the Korsch telescope was studied. In the case of an optical system having a complex asymmetrical structure, there is a limit to implementing the satellite structure by applying the coefficient of thermal expansion (CTE) in the optical-design software, so it is difficult to evaluate the performance of the optical system against temperature changes. To solve this problem, using mechanical design software all length changes were implemented in all structures that affect the optical system according to temperature, and the value of the change in distance between optical components due to temperature change was organized. Also, the values of changes in shape and thickness of the optical components against temperature changes are organized in the optical-design software. All changes derived from both software packages were applied in the optical software to evaluate the performance of the optical system. As a result, it was found that the MTF for a spatial resolution of 71.4 cycles/mm was maintained at more than 25% in the range from 9 ℃ to 33 ℃. In addition, the performance of the optical system applying the improved structure was evaluated, by finding the structure that had the most influence on the optical system’s performance change, and deriving an athermal structure to reduce the effect. As a result, it was found that the MTF for a resolution of 71.4 cycles/mm was maintained at over 67% in the range from 9 ℃ to 33 ℃.
