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Combination of apodized pupil and phase mask coronagraph for SCExAO at Subaru Telescope

Nishikawa, Jun and Murakami, Naoshi and Lozi, Julien and Guyon, Olivier and Habu, Keiichiro and Ichien, Hikaru and Yoneta, Kenta and Sudoh, Seiji and Kumaki, Kosuke and Kumagai, Shiomi and Jovanovic, Nemanja and Martinache, Frantz (2020) Combination of apodized pupil and phase mask coronagraph for SCExAO at Subaru Telescope. In: Ground-based and Airborne Instrumentation for Astronomy VIII. Proceedings of SPIE. No.11447. Society of Photo-Optical Instrumentation Engineers (SPIE) , Bellingham, WA, Art. No. 114474T. ISBN 9781510636811.

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Subaru telescope has been operating a high-contrast imaging instruments called Subaru coronagraphic extreme adaptive optics (SCExAO) which is used for exoplanet research. We are developing phase mask coronagraphs using photonic crystal wave plates inside the SCExAO. An eight-octant phase mask (8OPM) of three-layer achromatic structure has been fabricated as a second generation. It was designed for J and H band to reach 10⁻⁵ contrast, and Ks band to 10⁻⁴. A retardation and a coronagraphic performance of the 8OPM were confirmed almost as designed at 1550nm. An apodised (binary shaped) pupil to be used with the 8OPM was also studied to suppress diffracted light by the secondary shadow and spiders. We confirmed a performance of the combination of the apodizer and the 8OPM at visible wavelengths in a lab. We optimized the apodizer for a pupil of the SCExAO where we obtained a transmission of 50 % and a contrast of 10⁻⁴ the center and 10⁻⁶ at outer region. We manufactured the designed apodizer to be installed in SCExAO for infrared observations.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Lozi, Julien0000-0002-3047-1845
Guyon, Olivier0000-0002-1097-9908
Jovanovic, Nemanja0000-0001-5213-6207
Martinache, Frantz0000-0003-1180-4138
Additional Information:© 2020 Society of Photo-Optical Instrumentation Engineers (SPIE). This work was supported partly by JSPS KAKENHI (Grant Number 19H01932) and Astrobiology Center Project (AB301009). Experiments were made at a lab in the Advanced Technology Center of the NAOJ.
Funding AgencyGrant Number
Japan Society for the Promotion of Science (JSPS)19H01932
National Institutes of Natural Sciences of JapanAB301009
Subject Keywords:exoplanet, coronagraph, adaptive optics, phase mask, apodizer, shaped pupil
Series Name:Proceedings of SPIE
Issue or Number:11447
Record Number:CaltechAUTHORS:20201218-082742321
Persistent URL:
Official Citation:Jun Nishikawa, Naoshi Murakami, Julien Lozi, Olivier Guyon, Keiichiro Habu, Hikaru Ichien, Kenta Yoneta, Seiji Sudoh, Kosuke Kumaki, Shiomi Kumagai, Nemanja Jovanovic, and Frantz Martinache "Combination of apodized pupil and phase mask coronagraph for SCExAO at Subaru Telescope", Proc. SPIE 11447, Ground-based and Airborne Instrumentation for Astronomy VIII, 114474T (13 December 2020);
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:107185
Deposited By: Tony Diaz
Deposited On:18 Dec 2020 16:45
Last Modified:16 Nov 2021 19:00

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