Nulling stellar coronagraph with an adaptive phase mask

• Project/Area Number: 25610038
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Astronomy
• Research Institution: Hokkaido University
• Principal Investigator: BABA Naoshi 北海道大学, ―, 名誉教授 (70143261)
• Co-Investigator(Renkei-kenkyūsha): TAMURA Motohide 東京大学, 大学院理学研究科, 教授 (00260018) ; MURAKAMI Naoshi 北海道大学, 大学院工学研究院, 助教 (80450188) ; MIURA Noriaki 北見工業大学, 工学部, 教授 (30209720)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2015: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2014: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000); Fiscal Year 2013: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
• Keywords: 光学赤外線天文学 / 系外惑星 / ステラコロナグラフ / ナル干渉

Outline of Final Research Achievements

Phase-mask coronagraph holds the ability to directly detect exoplanets. The problem here is that ordinary telescopes do not have perfect circular apertures but shades of a secondary mirror and spiders. It is known that shades of a secondary mirror and spiders deteriorate significantly the performance of phase-mask coronagraph. There have been proposed several ideas to overcome the deterioration. However, these ideas are based on using theoretically established phase-masks.
We developed a new kind of phase mask that would perform the contrast ratio of more than the tenth power of 10 for a circular aperture with shades of a secondary mirror and spiders. The phase distribution of the phase mask is numerically obtained by letting the leaked light outside the transparent part of the pupil. We applied the hybrid input-output algorithm, one of phase retrieval methods, to find the phase distribution of the phase mask. We showed the characteristics of thus obtained phase mask.

Research Products

• [Journal Article] Numerically designed phase-mask for stellar coronagraph (2015)
  • Author(s): N. Baba, N. Murakami, N. Miura, and M. Tamura
  • Journal Title: Proc. SPIE Volume: 9605 Pages: 96051V-96051V
  • DOI: 10.1117/12.2186498
  • NAID: 120006671845
  • Open Access / Acknowledgement Compliant
• [Journal Article] Recent progress on phase-mask coronagraphy based on photonic-crystal technology (2014)
  • Author(s): Murakami, Naoshi, Nishikawa, Jun, Tamura, Motohide, Serabyn, Eugene, Traub, Wesley A., Liewer, Kurt M., Moody, Dwight C., Trauger, John T., Guyon, Olivier, Martinache, Frantz, and 8 coauthors
  • Journal Title: Proceedings of the SPIE Volume: 9143 Pages: 914334-914334
  • DOI: 10.1117/12.2054790
  • Peer Reviewed
• [Journal Article] Central-obscuration removal plates for focal-plane phase-mask coronagraphs with a centrally-obscured telescope (2014)
  • Author(s): F. Oshiyama, N. Murakami, O. Guyon, F. Martinache, N. Baba, T. Matsuo, J. Nishikawa, and M. Tamura
  • Journal Title: Publ. Astron. Soc. Pacific Volume: 126 Pages: 270-279
  • NAID: 120005553688
  • Peer Reviewed
• [Presentation] 広帯域極限高コントラスト観測を目指した3層8分割位相マスクの開発 (2016)
  • Author(s): 村上尚史、西川淳、R. Galicher, P. Baudoz, 小室祐介、赤岩夏海、馬場直志、田村元秀
  • Organizer: 日本天文学会2016年春季年会
  • Place of Presentation: 首都大学東京（八王子市）
  • Year and Date: 2016-03-15
• [Presentation] 太陽系外惑星直接検出のための技術開発 (2016)
  • Author(s): 馬場直志
  • Organizer: 平成27年度光産業技術シンポジウム‐光加工・計測が創る新たな社会と産業イノベーション‐
  • Place of Presentation: リーガロイヤルホテル東京（東京都新宿区）
  • Year and Date: 2016-02-03
  • Invited
• [Presentation] 瞳再配置光学系による位相マスクコロナグラフの実証実験 (2015)
  • Author(s): 赤岩夏海、村上尚史，西川淳、田村元秀、馬場直志
  • Organizer: 日本天文学会2015年秋季年会
  • Place of Presentation: 甲南大学（神戸市）
  • Year and Date: 2015-09-09
• [Presentation] 太陽補償光学系の開発と補償効果のシミュレーション（２） (2015)
  • Author(s): 三浦則明、大石明、桑村 進、馬場直志、花岡庸一郎、北井礼三郎、上野悟、仲谷善一、一本潔
  • Organizer: 日本天文学会2015年秋季年会
  • Place of Presentation: 甲南大学（神戸市）
  • Year and Date: 2015-09-09
• [Presentation] Numerically designed phase-mask for stellar coronagraph (2015)
  • Author(s): N. Baba, N. Murakami, N. Miura, and M. Tamura
  • Organizer: SPIE Optics+Photonics Conference
  • Place of Presentation: San Diego Convention Center, San Diego, USA
  • Year and Date: 2015-08-09
  • Int'l Joint Research
• [Presentation] ステラコロナグラフ用位相マスクの数値的デザイン (2015)
  • Author(s): 馬場直志、村上尚史、三浦則明、田村元秀
  • Organizer: 日本天文学会2015年春季年会
  • Place of Presentation: 大阪大学（豊中）
  • Year and Date: 2015-03-18 – 2015-03-21
• [Presentation] Towards direct imaging of exoplanets (2015)
  • Author(s): N. Baba, Y. Nakai, and N. Murakami
  • Organizer: International Conference on Optics and Photonics (ICOP2015)
  • Place of Presentation: Calcutta Univ. (Kolkata, India)
  • Year and Date: 2015-02-20 – 2015-02-22
  • Invited
• [Presentation] Recent progress on phase-mask coronagraphy based on photonic-crystal technology (2014)
  • Author(s): N. Murakami, J. Nishikawa, M. Tamura, E. Serabyn, W. Traub, K. Liever, D. Moody, J. Trauger, O. Guyon, F. Martinache, N. Jovanovic, G. Sigh, F. Oshiyama, H. Shoji, M. Sakamoto, S. Hamaguchi, K. Oka, and N. Baba
  • Organizer: SPIE Conf. on Astronomical Telescopes and Instrumentation 2014
  • Place of Presentation: Montreal, Canada
  • Year and Date: 2014-06-22 – 2014-06-27
• [Presentation] すばる望遠鏡搭載に向けた8分割位相マスクコロナグラフの開発(III)
  • Author(s): 押山史佳，村上尚史，平翼、馬場直志、O. Guyon, N. Jovanovic, G. Singh, F. Martinache, 西川淳、田村元秀、松尾太郎
  • Organizer: 日本天文学会2014年春季年会
  • Place of Presentation: 国際基督教大学（三鷹）