A high-contrast coronagraph for direct imaging of Earth-like exoplanets: design and test  

作　　者：Cheng-Chao Liu De-Qing Ren Jiang-Pei Dou Yong-Tian Zhu Xi Zhang Gang Zhao Zhen Wu Rui Chen 

机构地区：[1]National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology,Chinese Academy of Sciences [2]Key Laboratory of Astronomical Optics & Technology, National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology, Chinese Academy of Sciences [3]University of Chinese Academy of Sciences [4]Physics & Astronomy Department, California State University Northridge

出　　处：《Research in Astronomy and Astrophysics》2015年第3期453-460,共8页天文和天体物理学研究（英文版）

基　　金：Supported by the National Natural Science Foundation of China

摘　　要：A high-contrast coronagraph for direct imaging of an Earth-like exoplanet at the visible band needs a contrast of 10^-10 at a small angular separation of 4λ/D or less. Here we report our recent laboratory experiment that approaches these lim- its. Our test of a high-contrast imaging coronagraph is based on our step-transmission apodized filter. To achieve this goal, we use a liquid crystal array as a phase correc- tor to create a dark hole based on our dedicated algorithm. We have suppressed the diffraction and speckle noise near the point image of a star to a level of 1.68 × 10^-9 at 4λ/D, which can be used for direct imaging of Jupiter-like exoplanets. This demon- strates that a telescope incorporating a high-contrast coronagraph in space has the potential to detect and characterize Earth-like planets.A high-contrast coronagraph for direct imaging of an Earth-like exoplanet at the visible band needs a contrast of 10^-10 at a small angular separation of 4λ/D or less. Here we report our recent laboratory experiment that approaches these lim- its. Our test of a high-contrast imaging coronagraph is based on our step-transmission apodized filter. To achieve this goal, we use a liquid crystal array as a phase correc- tor to create a dark hole based on our dedicated algorithm. We have suppressed the diffraction and speckle noise near the point image of a star to a level of 1.68 × 10^-9 at 4λ/D, which can be used for direct imaging of Jupiter-like exoplanets. This demon- strates that a telescope incorporating a high-contrast coronagraph in space has the potential to detect and characterize Earth-like planets.

关 键 词：instrumentation： coronagraph liquid crystal array -- techniques：apodization -- methods： laboratory 

分 类 号：P111.41[天文地球—天文学]