A high-contrast coronagraph for direct imaging of Earth-like exoplanets: design and test**Supported by the National Natural Science Foundation of China. (March 2015)

• Record Type: Journal Article
• Authors: Liu, Cheng-Chao; Ren, De-Qing; Dou, Jian-Pei; Zhu, Yong-Tian; Zhang, Xi; Zhao, Gang; Wu, Zhen; Chen, Rui
• Is Part Of: Research in astronomy and astrophysics. Volume 15:Number 3(2015:Mar.)
• Page Start: 453
• Page End: 460
• Publication Date: 2015-03
• Subjects: instrumentation: coronagraph, liquid crystal array -- techniques: apodization -- methods: laboratory; Astronomy -- Periodicals; Astrophysics -- Periodicals; 520.5
• DOI: 10.1088/1674-4527/15/3/012
• Languages: English
• ISSNs: 1674-4527

Abstract

Abstract: 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 limits. 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 corrector 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 demonstrates that a telescope incorporating a high-contrast coronagraph in space has the potential to detect and characterize Earth-like planets.