Dr. Naoshi Murakami Profile

Dr. Naoshi Murakami

Lecturer at Hokkaido Univ

SPIE Involvement:

Author

Publications (52)

Proceedings Article | 5 October 2023 Presentation + Paper

Presentation + Paper

Development of the coherent differential imaging on speckle area nulling (CDI-SAN) method

Kenta Yoneta, Jun Nishikawa, Yutaka Hayano, Masatsugu Iribe, Kodai Yamamoto, Ryo Tsukui, Naoshi Murakami, Mizuki Asano, Hiromu Muramatsu, Yosuke Tanaka, Motohide Tamura, Takahiro Sumi, Toru Yamada, Olivier Guyon, Julien Lozi, Vincent Deo, Sébastien Vievard, Kyohoon Ahn

Proceedings Volume 12680, 126800D (2023) https://doi.org/10.1117/12.2676294

KEYWORDS: Modulation, Coherence imaging, Speckle, Electric fields, Equipment, Wavefronts, Telescopes, Optical coherence, Exoplanets

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Proceedings Article | 27 August 2022 Presentation + Paper

Presentation + Paper

Recent progress of the facility for coronagraphic elemental technologies (FACET)

Kenta Yoneta, Seiji Sudoh, Hiroaki Hayashi, Mizuki Asano, Jun Nishikawa, Naoshi Murakami

Proceedings Volume 12180, 1218027 (2022) https://doi.org/10.1117/12.2628451

KEYWORDS: Coronagraphy, Spatial light modulators, Exoplanets, Wavefronts, Halftones

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SPIE Journal Paper | 11 March 2021 Open Access

Open Access

Mid-infrared spectrometer and camera for the Origins Space Telescope

Itsuki Sakon, Thomas Roellig, Kimberly Ennico-Smith, Taro Matsuo, Yuji Ikeda, Tomoyasu Yamamuro, Keigo Enya, Takehiko Wada, Mitsunobu Kawada, Aoi Takahashi, Yuki Sarugaku, Naofumi Fujishiro, Naoshi Murakami, Jun Nishikawa, Takayuki Kotani, Shohei Goda, Masayuki Ido, Satoshi Itoh, Takahiro Tsuboi, Takahiro Sumi, Masatsugu Kamiura, Takeo Manome, Naoto Iida, Kentaro Yanagibashi, Thomas Greene, Bernardus Helvensteijn, Lynn Hofland, Roy Johnson, Ali Kashani, Emmett Quigley, Robert McMurray, Hanae Inami, Denis Burgarella, the Origins Space Telescope mission concept study team

JATIS, Vol. 7, Issue 01, 011013, (March 2021) https://doi.org/10.1117/12.10.1117/1.JATIS.7.1.011013

KEYWORDS: Sensors, Spectroscopy, Mirrors, Cameras, Mid-IR, Space telescopes, Electronics, Telescopes, Detector arrays, Mercury cadmium telluride

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The mid-infrared spectrometer and camera transit spectrometer (MISC-T) is one of the three baseline instruments for Origins Space Telescope (Origins) and provides the capability to assess the habitability of nearby exoplanets and search for signs of life. MISC-T employs a densified pupil optical design, and HgCdTe and Si:As detector arrays. This optical design allows the instrument to be relatively insensitive to minor line-of-sight pointing drifts and telescope aberrations, and the detectors do not require a sub-Kelvin refrigerator. MISC-T has three science spectral channels that share the same field-of-view by means of beam splitters, and all channels are operated simultaneously to cover the full spectral range from 2.8 to 20 μm at once with exquisite stability and precision (<5 ppm between 2.8 to 11 μm, <20 ppm between 11 and 20 μm). A Lyot-coronagraph-based tip–tilt sensor located in the instrument fore-optics uses the light reflected by a field stop, which corresponds to 0.3% of the light from the target, to send fine pointing information to the field steering mirror in the Origins telescope. An additional MISC Wide Field Imager (WFI) is studied as an upscope option for the Origins. MISC-WFI offers a wide field imaging (3 ′ × 3 ′ ) and low-resolution spectroscopic capability with filters and grating-prisms (grisms) covering 5 to 28 μm. The imaging capability of the MISC-WFI will be used for general science objectives. The low-resolution spectroscopic capability in MISC-WFI with a resolving power R ( = λ / Δλ) of a few hundreds will be used to measure the mid-infrared dust features and ionic lines at z up to ∼1 in the Origins mission’s Rise of Metals and Black Hole Feedback programs. The MISC-WFI also serves as a focal plane pointing and guiding instrument for the observatory, including when the MISC-T channel is performing its exoplanet spectroscopy observations.

Proceedings Article | 13 December 2020 Presentation + Paper

Presentation + Paper

Construction of EXIST (Exoplanet Imaging System Testbed) toward future space coronagraphs

Naoshi Murakami, Kenta Yoneta, Hikaru Ichien, Seiji Sudoh, Keiichiro Habu, Jun Nishikawa

Proceedings Volume 11443, 114432M (2020) https://doi.org/10.1117/12.2560450

KEYWORDS: Coronagraphy, Imaging systems, Exoplanets, Spatial light modulators, Speckle, Astronomy, Stars, Optical components, Wavefronts, Control systems

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Proceedings Article | 13 December 2020 Poster + Paper

Poster + Paper

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

Jun Nishikawa, Naoshi Murakami, Julien Lozi, Olivier Guyon, Keiichiro Habu, Hikaru Ichien, Kenta Yoneta, Seiji Sudoh, Kosuke Kumaki, Shiomi Kumagai, Nemanja Jovanovic, Frantz Martinache

Proceedings Volume 11447, 114474T (2020) https://doi.org/10.1117/12.2560839

KEYWORDS: Coronagraphy, Telescopes, Manufacturing, Infrared telescopes, Wave plates, Binary data, Etching, Adaptive optics, Visible radiation, Wavefronts

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Proceedings Article | 13 December 2020 Poster + Paper

Poster + Paper

Speckle reduction technique using the self-coherent camera for the common-path visible nulling coronagraph

Kenta Yoneta, Naoshi Murakami, Koki Yoshida, Ryuta Koike, Takayuki Kotani, Hajime Kawahara, Naoshi Baba, Motohide Tamura

Proceedings Volume 11451, 114513Y (2020) https://doi.org/10.1117/12.2560471

KEYWORDS: Speckle, Cameras, Coronagraphy, Spatial light modulators, Nulling interferometry, Exoplanets, Polarizers, Interferometry, Beam splitters, Calcite

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Proceedings Article | 13 December 2020 Presentation + Paper

Presentation + Paper

Status of the SCExAO instrument: recent technology upgrades and path to a system-level demonstrator for PSI

Julien Lozi, Olivier Guyon, Sébastien Vievard, Ananya Sahoo, Vincent Deo, Nemanja Jovanovic, Barnaby Norris, Marc-Antoine Martinod, Ben Mazin, Alex Walter, Neelay Fruitwala, Sarah Steiger, Kristina Davis, Peter Tuthill, Tomoyuki Kudo, Hajime Kawahara, Takayuki Kotani, Michael Ireland, Theodoros Anagnos, Chrstian Schwab, Nick Cvetojevic, Elsa Huby, Sylvestre Lacour, Kevin Barjot, Tyler Groff, Jeffrey Chilcote, Jeremy Kasdin, Frantz Martinache, Romain Laugier, Mamadou N'Diaye, Justin Knight, Jared Males, Steven Bos, Frans Snik, David Doelman, Kelsey Miller, Eduardo Bendek, Ruslan Belikov, Eugene Pluzhnik, Thayne Currie, Masayuki Kuzuhara, Taichi Uyama, Jun Nishikawa, Naoshi Murakami, Jun Hashimoto, Yosuke Minowa, Christophe Clergeon, Yoshito Ono, Naruhisa Takato, Motohide Tamura, Hideki Takami, Masa Hayashi

Proceedings Volume 11448, 114480N (2020) https://doi.org/10.1117/12.2562832

KEYWORDS: Imaging systems, Telescopes, Infrared sensors, Infrared imaging, Coronagraphy, Wavefront sensors, Sensors, Detection and tracking algorithms, Cameras, Wavefronts

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Proceedings Article | 24 July 2018 Presentation + Paper

Presentation + Paper

The mid-infrared imager, spectrometer, coronagraph (MISC) for the Origins Space telescope (OST)

Itsuki Sakon, Thomas Roellig, Kimberly Ennico-Smith, Taro Matsuo, Yuji Ikeda, Tomoyasu Yamamuro, Naofumi Fujishiro, Keigo Enya, Aoi Takahashi, Takehiko Wada, Olivier Guyon, Takayuki Kotani, Jun Nishikawa, Naoshi Murakami, Yuki Sarugaku, Denis Burgarella

Proceedings Volume 10698, 1069817 (2018) https://doi.org/10.1117/12.2314177

KEYWORDS: Spectroscopy, Coronagraphy, Space telescopes, Imaging systems, Mid-IR, Imaging spectroscopy, Exoplanets, Sensors, Telescopes

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The Mid-infrared Imager, Spectrometer, Coronagraph (MISC) is one of the instruments studied both for the Origins Space Telescope (OST) Mission Concept 1 and 2. The MISC for OST Mission Concept 1 consists of the MISC imager and spectrometer module (MISC I and S), the MISC coronagraph module (MISC COR) and the MISC transit spectrometer module (MISC TRA). The MISC I and S offers (1) a wide field (3 arcminx3 arcmin) imaging and low-resolution spectroscopic capability with filters and grisms for 6-38 μm, (2) a medium-resolution (R~1,000) Integral Field Unit (IFU) spectroscopic capability for 5- 38 μm and (3) a high-resolution (R~25,000) slit spectroscopic capability for 12-18 μm and 25-36 μm. The MISC COR module employs PIAACMC coronagraphy method and covers 6-38 μm achieving 10-7 contrast at 0.5 arcsec from the central star. The MISC TRA module employs a densified pupil spectroscopic design to achieve 3-5 ppm of spectro-photometric stability and covers 5-26 μm with R=100-300. The MISC for OST Mission Concept 2 consists of the MISC wide field imager module (MISC WFI) and the MISC transit Spectrometer module (MISC TRA). The MISC WFI offers a wide field (3 arcmin ×3 arcmin) imaging and low-resolution spectroscopic capabilities with filters and grisms for 6-28μm. The MISC TRA module in the OST Mission Concept 2 also employs the densified pupil spectroscopic design to achieve <5 ppm of spectro-photometric stability and covers 4-22 μm with R=100-300. The highest ever spectrophotometric stability achieved by MISC TRA enables to detect bio-signatures (e.g., ozone, water, and methane) in habitable worlds in both primary and secondary transits of exoplanets and makes the OST a powerful tool to bring an revolutionary progress in exoplanet sciences. Combined with the spectroscopic capability in the FIR provided by other OST instruments, the MISC widens the wavelength coverage of OST down to 5μm, which makes the OST a powerful tool to diagnose the physical and chemical condition of the ISM using dust features, molecules lines and atomic and ionic lines. The MISC also provides the OST with a focal plane guiding function for the other OST science instruments as well as its own use.

Proceedings Article | 10 July 2018 Paper

Paper

PIAA coronagraph for Origins Space telescope (OST) mid-infrared imager, spectrometer, coronagraph (MISC) instrument

N. Fujishiro, I. Sakon, K. Enya, O. Guyon, J. Nishikawa, N. Murakami, T. Kotani, M. Tamura, A. Takahashi, T. Roellig, K. Ennico-Smith

Proceedings Volume 10706, 107065N (2018) https://doi.org/10.1117/12.2313066

KEYWORDS: Coronagraphy, Apodization, Mirrors, Geometrical optics, Space telescopes, Segmented mirrors, Mid-IR, Diffraction, Imaging systems, Spectroscopy

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Proceedings Article | 8 August 2016 Paper

Paper

Image restoration for a hypertelescope

Yuto Nakai, Naoshi Baba, Naoshi Murakami, Noriaki Miura, Motohide Tamura

Proceedings Volume 9907, 99073F (2016) https://doi.org/10.1117/12.2231920

KEYWORDS: Image restoration, Telescopes, Image quality, Exoplanets, Point spread functions, Interferometry, Computer simulations, Sensors, Astronomy, Coronagraphy

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Proceedings Article | 1 August 2016 Paper

Paper

Contrast improvement with imperfect pre-coronagraph and dark-hole

Jun Nishikawa, Masahito Oya, Naoshi Murakami, Motohide Tamura, Takashi Kurokawa, Yosuke Tanaka, Shiomi Kumagai, Takayuki Kotani

Proceedings Volume 9904, 99043E (2016) https://doi.org/10.1117/12.2232920

KEYWORDS: Deformable mirrors, Interferometers, Nulling interferometry, Wavefronts, Adaptive optics, Stars, Exoplanets, Coronagraphy, Speckle, Photomasks

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Proceedings Article | 22 July 2016 Paper

Paper

Development of speckle nulling technique for the Savart-plate lateral-shearing interferometric nuller for exoplanets (SPLINE)

Kenta Yoneta, Naoshi Murakami, Takayuki Kotani, Hajime Kawahara, Taro Matsuo, Naoshi Baba, Motohide Tamura

Proceedings Volume 9912, 99126I (2016) https://doi.org/10.1117/12.2231950

KEYWORDS: Speckle, Exoplanets, Nulling interferometry, Polarizers, Beam splitters, Wavefronts, Interferometry, Coronagraphy, Computer simulations, Modulation

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Proceedings Article | 22 July 2016 Paper

Paper

A three-layer eight-octant phase mask towards broadband high-contrast observations

Naoshi Murakami, Jun Nishikawa, Natsumi Akaiwa, Yusuke Komuro, Naoshi Baba, Motohide Tamura

Proceedings Volume 9912, 99126G (2016) https://doi.org/10.1117/12.2231946

KEYWORDS: Exoplanets, Photonic crystals, Polarization, Coronagraphy, Light sources, Stars, Jones calculus, Space telescopes, Telescopes, Optical filters

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Proceedings Article | 11 September 2015 Paper

Paper

Numerically designed phase-mask for stellar coronagraph

Naoshi Baba, Naoshi Murakami, Noriaki Miura, Motohide Tamura

Proceedings Volume 9605, 96051V (2015) https://doi.org/10.1117/12.2186498

KEYWORDS: Point spread functions, Coronagraphy, Exoplanets, Mirrors, Stars, Optical filtering, Telescopes, Phase retrieval, Astronomy, Liquid crystals

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Proceedings Article | 28 August 2014 Paper

Paper

Recent progress on phase-mask coronagraphy based on photonic-crystal technology

Naoshi Murakami, Jun Nishikawa, Motohide Tamura, Eugene Serabyn, Wesley Traub, Kurt Liewer, Dwight Moody, John Trauger, Olivier Guyon, Frantz Martinache, Nemanja Jovanovic, Garima Singh, Fumika Oshiyama, Hayato Shoji, Moritsugu Sakamoto, Shoki Hamaguchi, Kazuhiko Oka, Naoshi Baba

Proceedings Volume 9143, 914334 (2014) https://doi.org/10.1117/12.2054790

KEYWORDS: Coronagraphy, Manufacturing, Photomasks, Spiral phase plates, Space telescopes, Telescopes, Light sources, Polarizers, Adaptive optics, Polarization

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Proceedings Article | 28 August 2014 Paper

Paper

Adaptive optics operation with focal wavefront sensor in a coronagraph for direct observation of exoplanets

Masahito Oya, Jun Nishikawa, Masaaki Horie, Kazuma Sato, Masao Fukase, Naoshi Murakami, Takayuki Kotani, Shiomi Kumagai, Motohide Tamura, Yosuke Tanaka, Takashi Kurokawa

Proceedings Volume 9143, 91433B (2014) https://doi.org/10.1117/12.2055670

KEYWORDS: Speckle, Coronagraphy, Wavefronts, Adaptive optics, Wavefront sensors, Sensors, Interferometers, Modulation, Astronomical imaging, Nulling interferometry

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Proceedings Article | 2 August 2014 Paper

Paper

A coronagraph system with unbalanced nulling interferometer: progress of optics and control method

Jun Nishikawa, Masahito Oya, Masaaki Horie, Kazuma Sato, Masao Fukase, Naoshi Murakami, Takayuki Kotani, Shiomi Kumagai, Motohide Tamura, Yosuke Tanaka, Takashi Kurokawa

Proceedings Volume 9143, 91433A (2014) https://doi.org/10.1117/12.2055636

KEYWORDS: Coronagraphy, Adaptive optics, Wavefronts, Interferometers, Nulling interferometry, Wavefront aberrations, Stars, Control systems, Planets, Speckle

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Proceedings Article | 18 July 2014 Paper

Paper

Laboratory demonstration of the Savart-plate lateral-shearing interferometric nuller for exoplanets (SPLINE)

Hirofumi Kitou, Naoshi Murakami, Manabu Kida, Naoshi Baba, Taro Matsuo, Takayuki Kotani, Hajime Kawahara, Motohide Tamura

Proceedings Volume 9151, 91515N (2014) https://doi.org/10.1117/12.2055287

KEYWORDS: Wavefronts, Exoplanets, Polarizers, Interferometry, Surface plasmons, Liquid crystals, Light sources, Polarization, Nulling interferometry, Optical components

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Proceedings Article | 14 July 2014 Paper

Paper

High-contrast planet imager for Kyoto 4m segmented telescope

Taro Matsuo, Naoshi Murakami, Takayuki Kotani, Hajime Kawahara, Noriaki Natsume, Masaru Kino, Kodai Yamamoto, Hiroaki Imada, Mikio Kurita, Masatsugu Iribe, Hideya Nishida, Manabu Kida, Hirofumi Kitou, Kumi Ishikawa, Yutaka Uda, Hitoshi Tokoro, Tetsuya Nagata, Fumihide Iwamuro, Noriaki Miura, Shin Oya, Yoichi Itoh, Hiroshi Shibai, Motohide Tamura

Proceedings Volume 9147, 91471V (2014) https://doi.org/10.1117/12.2055751

KEYWORDS: Sensors, Telescopes, Adaptive optics, Wavefronts, Point spread functions, Wavefront sensors, Stars, Cameras, Coronagraphy, Planets

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Proceedings Article | 8 July 2014 Paper

Paper

Development and recent results from the Subaru coronagraphic extreme adaptive optics system

N. Jovanovic, O. Guyon, F. Martinache, C. Clergeon, G. Singh, T. Kudo, K. Newman, J. Kuhn, E. Serabyn, B. Norris, P. Tuthill, P. Stewart, E. Huby, G. Perrin, S. Lacour, S. Vievard, N. Murakami, O. Fumika, Y. Minowa, Y. Hayano, J. White, O. Lai, F. Marchis, G. Duchene, T. Kotani, J. Woillez

Proceedings Volume 9147, 91471Q (2014) https://doi.org/10.1117/12.2057249

KEYWORDS: Wavefront sensors, Point spread functions, Coronagraphy, Adaptive optics, Wavefronts, Speckle, Cameras, Deformable mirrors, Sensors, Imaging systems

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Proceedings Article | 17 October 2012 Paper

Paper

Unbalanced nulling interferometer with four-quadrant phase mask

Takuji Kobayashi, Jun Nishikawa, Yosuke Tanaka, Takashi Kurokawa, Ken Kashiwagi, Naoshi Murakami, Naoshi Baba, Nobuyuki Hashimoto

Proceedings Volume 8421, 84213D (2012) https://doi.org/10.1117/12.975179

KEYWORDS: Wavefronts, Adaptive optics, Interferometers, Exoplanets, Nulling interferometry, Picture Archiving and Communication System, Coronagraphy, Stars, Planets, Phase interferometry

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Proceedings Article | 24 September 2012 Paper

Paper

Development of the Savart-plate lateral-shearing interferometric nuller for exoplanet (SPLINE)

Naoshi Murakami, Manabu Kida, Naoshi Baba, Taro Matsuo, Takayuki Kotani, Hajime Kawahara, Yuka Fujii, Motohide Tamura

Proceedings Volume 8446, 84468H (2012) https://doi.org/10.1117/12.925605

KEYWORDS: Nulling interferometry, Stars, Polarizers, Interferometers, Telescopes, Light sources, Polarization, Exoplanets, Interferometry, Thirty Meter Telescope

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Proceedings Article | 24 September 2012 Paper

Paper

Second-Earth imager for TMT (SEIT): concept and its numerical simulation

Taro Matsuo, Takayuki Kotani, Naoshi Murakami, Hajime Kawahara, Yuka Fujii, Shin Oya, Mikio Kurita, Noriaki Natsume, Norio Narita, Kenji Takizawa, Masahiro Ikoma, Jun Minagawa, Naoshi Baba, Motohide Tamura

Proceedings Volume 8446, 84461K (2012) https://doi.org/10.1117/12.926039

KEYWORDS: Planets, Interferometers, Stars, Oxygen, Absorption, Coronagraphy, Speckle, Adaptive optics, Imaging systems, Thirty Meter Telescope

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Proceedings Article | 21 September 2012 Paper

Paper

SPICA coronagraph instrument: characterization of atmospheres and physical parameters of giant planets by direct imaging and spectroscopy

T. Kotani, K. Enya, T. Nakagawa, H. Matsuhara, H. Kataza, M. Kawada, M. Mita, K. Komatsu, H. Uchida, K. Fujiwara, S. Mitani, S. Sakai, K. Haze, H. Kaneda, S. Oyabu, D. Ishihara, T. Miyata, S. Sako, T. Nakamura, K. Asano, M. Tamura, J. Nishikawa, T. Yamashita, N. Narita, H. Hayano, S. Oya, E. Kokubo, Y. Itoh, T. Matsuo, M. Fukagawa, H. Shibai, M. Honda, N. Baba, N. Murakami, Y. Okamoto, S. Ida, M. Takami, L. Abe, O. Guyon, T. Yamamuro

Proceedings Volume 8442, 84420F (2012) https://doi.org/10.1117/12.925832

KEYWORDS: Coronagraphy, Imaging spectroscopy, Planets, Stars, Exoplanets, Point spread functions, Spectroscopy, Spectroscopes, Telescopes, Binary data

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Proceedings Article | 21 September 2012 Paper

Paper

A coronagraph system with unbalanced nulling interferometer: progress of dynamic range

Jun Nishikawa, Kaito Yokochi, Naoshi Murakami, Lyu Abe, Takayuki Kotani, Motohide Tamura, Takashi Kurokawa, Alexander Tavrov, Mitsuo Takeda, Hiroshi Murakami

Proceedings Volume 8442, 84425D (2012) https://doi.org/10.1117/12.925792

KEYWORDS: Coronagraphy, Wavefronts, Adaptive optics, Interferometers, Wavefront aberrations, Speckle, Picture Archiving and Communication System, Nulling interferometry, Mirrors, Feedback control

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Proceedings Article | 21 September 2012 Paper

Paper

Adaptive optics operation with two wavefront sensors in a coronagraph for exoplanet observations

Masahito Oya, Jun Nishikawa, Masaaki Horie, Naoshi Murakami, Takayuki Kotani, Lyu Abe, Shiomi Kumagai, Motohide Tamura, Takashi Kurokawa, Hiroshi Murakami

Proceedings Volume 8442, 844255 (2012) https://doi.org/10.1117/12.925858

KEYWORDS: Coronagraphy, Adaptive optics, Wavefronts, Wavefront sensors, Sensors, Speckle, Feedback loops, Picture Archiving and Communication System, Deformable mirrors, Stars

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Proceedings Article | 21 September 2012 Paper

Paper

Coronagraph focal-plane phase masks based on photonic crystal technology: recent progress and observational strategy

Naoshi Murakami, Jun Nishikawa, Wesley Traub, Dimitri Mawet, Dwight Moody, Brian Kern, John Trauger, Eugene Serabyn, Shoki Hamaguchi, Fumika Oshiyama, Moritsugu Sakamoto, Akitoshi Ise, Kazuhiko Oka, Naoshi Baba, Hiroshi Murakami, Motohide Tamura

Proceedings Volume 8442, 844205 (2012) https://doi.org/10.1117/12.925613

KEYWORDS: Coronagraphy, Polarization, Photonic crystals, Manufacturing, Photomasks, Stars, Polarimetry, Spiral phase plates, Phase shift keying, Planets

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Proceedings Article | 21 September 2012 Paper

Paper

Review of small-angle coronagraphic techniques in the wake of ground-based second-generation adaptive optics systems

Dimitri Mawet, Laurent Pueyo, Peter Lawson, Laurent Mugnier, Wesley Traub, Anthony Boccaletti, John Trauger, Szymon Gladysz, Eugene Serabyn, Julien Milli, Ruslan Belikov, Markus Kasper, Pierre Baudoz, Bruce Macintosh, Christian Marois, Ben Oppenheimer, Harrisson Barrett, Jean-Luc Beuzit, Nicolas Devaney, Julien Girard, Olivier Guyon, John Krist, Bertrand Mennesson, David Mouillet, Naoshi Murakami, Lisa Poyneer, Dmitri Savransky, Christophe Vérinaud, James Wallace

Proceedings Volume 8442, 844204 (2012) https://doi.org/10.1117/12.927245

KEYWORDS: Coronagraphy, Space telescopes, Telescopes, Adaptive optics, Stars, Spiral phase plates, Planets, Wavefronts, Cameras, Modulation

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Proceedings Article | 12 September 2012 Paper

Paper

Wavefront correction inside unbalanced nulling interferometer

Masaaki Horie, Jun Nishikawa, Masahito Oya, Naoshi Murakami, Lyu Abe, Ryo Waki, Shiomi Kumagai, Motohide Tamura, Takashi Kurokawa, Hiroshi Murakami

Proceedings Volume 8445, 84452E (2012) https://doi.org/10.1117/12.926737

KEYWORDS: Wavefronts, Adaptive optics, Interferometers, Coronagraphy, Algorithm development, Astronomical imaging, Planets, Astronomy, Nulling interferometry, Interferometry

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Proceedings Article | 15 September 2011 Paper

Paper

Taking the vector vortex coronagraph to the next level for ground- and space-based exoplanet imaging instruments: review of technology developments in the USA, Japan, and Europe

Dimitri Mawet, Naoshi Murakami, Christian Delacroix, Eugene Serabyn, Olivier Absil, Naoshi Baba, Jacques Baudrand, Anthony Boccaletti, Rick Burruss, Russell Chipman, Pontus Forsberg, Serge Habraken, Shoki Hamaguchi, Charles Hanot, Akitoshi Ise, Mikael Karlsson, Brian Kern, John Krist, Andreas Kuhnert, Marie Levine, Kurt Liewer, Stephen McClain, Scott McEldowney, Bertrand Mennesson, Dwight Moody, Hiroshi Murakami, Albert Niessner, Jun Nishikawa, Nada O'Brien, Kazuhiko Oka, Peggy Park, Pierre Piron, Laurent Pueyo, Pierre Riaud, Moritsugu Sakamoto, Motohide Tamura, John Trauger, David Shemo, Jean Surdej, Nelson Tabirian, Wesley Traub, James Wallace, Kaito Yokochi

Proceedings Volume 8151, 815108 (2011) https://doi.org/10.1117/12.896059

KEYWORDS: Coronagraphy, Polarization, Spiral phase plates, Photonic crystals, Liquid crystals, Polymers, Telescopes, Exoplanets, Space telescopes, Optics manufacturing

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Proceedings Article | 11 August 2010 Paper

Paper

A coronagraph system with unbalanced nulling interferometer: progress of wavefront correction

Jun Nishikawa, Kaito Yokochi, Naoshi Murakami, Lyu Abe, Takayuki Kotani, Motohide Tamura, Takashi Kurokawa, Alexander Tavrov, Mitsuo Takeda, Hiroshi Murakami

Proceedings Volume 7731, 77314O (2010) https://doi.org/10.1117/12.856945

KEYWORDS: Coronagraphy, Wavefronts, Adaptive optics, Nulling interferometry, Mirrors, Wavefront aberrations, Interferometers, Speckle, Beam splitters, Picture Archiving and Communication System

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Proceedings Article | 11 August 2010 Paper

Paper

Polarization-interferometric eight-octant phase-mask coronagraph using ferroelectric liquid crystal for exoplanet detection

Naoshi Murakami, Takeshi Inabe, Toshihiko Komatsu, Jun Nishikawa, Nobuyuki Hashimoto, Makoto Kurihara, Naoshi Baba, Motohide Tamura

Proceedings Volume 7731, 77314E (2010) https://doi.org/10.1117/12.856395

KEYWORDS: Coronagraphy, Manufacturing, Polarizers, Stars, Ferroelectric LCDs, Polarization, Optics manufacturing, Exoplanets, Photomasks, Exoplanetary science

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Proceedings Article | 16 July 2010 Paper

Paper

An eight-octant phase-mask coronagraph for the Subaru coronagraphic extreme AO (SCExAO) system: system design and expected performance

Naoshi Murakami, Olivier Guyon, Frantz Martinache, Taro Matsuo, Kaito Yokochi, Jun Nishikawa, Motohide Tamura, Takashi Kurokawa, Naoshi Baba, Frédéric Vogt, Vincent Garrel, Takashi Yoshikawa

Proceedings Volume 7735, 773533 (2010) https://doi.org/10.1117/12.858116

KEYWORDS: Coronagraphy, Telescopes, Polarizers, Space telescopes, Adaptive optics, Imaging systems, Apodization, Sensors, Wavefronts, Stars

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Proceedings Article | 28 July 2008 Paper

Paper

Recent progress at the MIRA: development of fringe tracking system

Naoko Ohishi, Masanori Yoshizawa, Jun Nishikawa, Naoshi Murakami, Yasuo Torii, Syunsaku Suzuki, Koichi Kubo, Hikaru Iwashita, Yoshinobu Kondo

Proceedings Volume 7013, 701305 (2008) https://doi.org/10.1117/12.788985

KEYWORDS: Interferometers, Polarimetry, Mirrors, Ferroelectric materials, Sensors, Control systems, Optical tracking, Spectroscopy, Interferometry, Domes

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Proceedings Article | 15 July 2008 Paper

Paper

Development of a dichroic beam splitter for Subaru AO188

Yosuke Minowa, Hideki Takami, Makoto Watanabe, Yutaka Hayano, Masaaki Miyake, Masanori Iye, Shin Oya, Masayuki Hattori, Naoshi Murakami, Olivier Guyon, Yoshihiko Saito, Meguru Itoh, Stephen Colley, Matthew Dinkins, Michael Eldred, Taras Golota

Proceedings Volume 7015, 701561 (2008) https://doi.org/10.1117/12.788597

KEYWORDS: Beam splitters, Transmittance, Optical coatings, Thin film coatings, Humidity, Near infrared, Telescopes, Adaptive optics, Thorium, Absorption

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Proceedings Article | 15 July 2008 Paper

Paper

Implementation of 188-element curvature-based wavefront sensor and calibration source unit for the Subaru LGSAO system

Makoto Watanabe, Shin Oya, Yutaka Hayano, Hideki Takami, Masayuki Hattori, Yosuke Minowa, Yoshihiko Saito, Meguru Ito, Naoshi Murakami, Masanori Iye, Olivier Guyon, Stephen Colley, Michael Eldred, Taras Golota, Matthew Dinkins

Proceedings Volume 7015, 701564 (2008) https://doi.org/10.1117/12.789882

KEYWORDS: Adaptive optics, Calibration, Wavefront sensors, Mirrors, Avalanche photodetectors, Stars, Laser guide stars, Cameras, Telescopes, Optical fibers

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Proceedings Article | 12 July 2008 Paper

Paper

Laboratory experiments on the 8-octant phase-mask coronagraph

Naoshi Murakami, Ryosuke Uemura, Naoshi Baba, Hiroshi Shibuya, Jun Nishikawa, Lyu Abe, Motohide Tamura, Nobuyuki Hashimoto

Proceedings Volume 7010, 70101J (2008) https://doi.org/10.1117/12.788145

KEYWORDS: Coronagraphy, Liquid crystals, Stars, Manufacturing, Numerical simulations, Polarization, Exoplanets, Helium neon lasers, Modulation, Astronomy

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Proceedings Article | 12 July 2008 Paper

Paper

Mid-infrared coronagraph for SPICA

K. Enya, L. Abe, K. Haze, S. Tanaka, T. Nakagawa, H. Kataza, S. Higuchi, T. Miyata, S. Sako, T. Nakamura, M. Tamura, J. Nishikawa, N. Murakami, Y. Itoh, T. Wakayama, T. Sato, N. Nakagiri, O. Guyon, M. Venet, P. Bierden

Proceedings Volume 7010, 70102Z (2008) https://doi.org/10.1117/12.788509

KEYWORDS: Coronagraphy, Space telescopes, Infrared telescopes, Cryogenics, Telescopes, Mirrors, Binary data, Infrared radiation, Microelectromechanical systems, James Webb Space Telescope

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The SPace Infrared telescope for Cosmology and Astrophysics (SPICA) is a infrared space-borne telescope mission of the next generation following AKARI. SPICA will carry a telescope with a 3.5 m diameter monolithic primary mirror and the whole telescope will be cooled to 5 K. SPICA is planned to be launched in 2017, into the sun-earth L2 libration halo orbit by an H II-A rocket and execute infrared observations at wavelengths mainly between 5 and 200 micron. The large telescope aperture, the simple pupil shape, the capability of infrared observations from space, and the early launch gives us with the SPICA mission a unique opportunity for coronagraphic observation. We have started development of a coronagraphic instrument for SPICA. The primary target of the SPICA coronagraph is direct observation of extra-solar Jovian planets. The main wavelengths of observation, the required contrast and the inner working angle (IWA) of the SPICA coronagraph are set to be 5-27 micron (3.5-5 micron is optional), 10^-6, and a few λ/D (and as small as possible), respectively, in which λ is the observation wavelength and D is the diameter of the telescope aperture (3.5m). For our laboratory demonstration, we focused first on a coronagraph with a binary shaped pupil mask as the primary candidate for SPICA because of its feasibility. In an experiment with a binary shaped pupil coronagraph with a He-Ne laser (λ=632.8nm), the achieved raw contrast was 6.7×10^-8, derived from the average measured in the dark region without active wavefront control. On the other hand, a study of Phase Induced Amplitude Apodization (PIAA) was initiated in an attempt to achieve better performance, i.e., smaller IWA and higher throughput. A laboratory experiment was performed using a He-Ne laser with active wavefront control, and a raw contrast of 6.5×10^-7 was achieved. We also present recent progress made in the cryogenic active optics for SPICA. Prototypes of cryogenic deformable by Micro Electro Mechanical Systems (MEMS) techniques were developed and a first demonstration of the deformation of their surfaces was performed with liquid nitrogen cooling. Experiments with piezo-actuators for a cryogenic tip-tilt mirror are also ongoing.

Proceedings Article | 12 July 2008 Paper

Paper

Polarization analysis as a means of detecting exoplanets and measuring their objective spectra

N. Zubko, N. Baba, N. Murakami

Proceedings Volume 7010, 70101P (2008) https://doi.org/10.1117/12.788538

KEYWORDS: Polarization, Planets, Exoplanets, Coronagraphy, Stars, Polarization analysis, Prisms, Destructive interference, Nulling interferometry, Imaging spectroscopy

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Proceedings Article | 12 July 2008 Paper

Paper

Virtual wavefront compensation and speckle reduction in coronagraph by unbalanced nulling interferometer (UNI) and phase and amplitude correction (PAC)

J. Nishikawa, K. Yokochi, L. Abe, N. Murakami, T. Kotani, M. Tamura, T. Kurokawa, A. V. Tavrov, M. Takeda

Proceedings Volume 7010, 70102A (2008) https://doi.org/10.1117/12.788895

KEYWORDS: Coronagraphy, Wavefronts, Adaptive optics, Picture Archiving and Communication System, Speckle, Wavefront aberrations, Interferometers, Stars, Wavefront compensation, Phase interferometry

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Proceedings Article | 10 July 2008 Paper

Paper

Current status of the laser guide star adaptive optic system for Subaru Telescope

Yutaka Hayano, Hideki Takami, Olivier Guyon, Shin Oya, Masayuki Hattori, Yoshihiko Saito, Makoto Watanabe, Naoshi Murakami, Yosuke Minowa, Meguru Ito, Stephen Colley, Michael Eldred, Taras Golota, Matthew Dinkins, Nobunari Kashikawa, Masanori Iye

Proceedings Volume 7015, 701510 (2008) https://doi.org/10.1117/12.789992

KEYWORDS: Adaptive optics, Telescopes, Stars, Laser guide stars, K band, Gold vapor lasers, Optical fibers, Waveguides, Sodium, Point spread functions

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Proceedings Article | 19 September 2007 Paper

Paper

Coronagraph project with the SPICA mission

K. Enya, L. Abe, S. Tanaka, K. Haze, M. Venet, T. Nakagawa, H. Kataza, M. Tamura, J. Nishikawa, N. Murakami, K. Fujita, Y. Itoh, O. Guyon, E. Pluzhnik, T. Wakayama, T. Sato, N. Nakagiri

Proceedings Volume 6693, 66930I (2007) https://doi.org/10.1117/12.733707

KEYWORDS: Coronagraphy, Space telescopes, Telescopes, Point spread functions, Mirrors, Infrared telescopes, Binary data, James Webb Space Telescope, Photomasks, Wavefronts

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We present the status of the development of a coronagraph for the Space Infrared telescope for Cosmology and Astrophysics (SPICA). SPICA is the next generation of infrared space-borne telescope missions following to AKARI, led by Japan. SPICA will carry a telescope that has a 3.5 m diameter monolithic primary mirror and the whole telescope will be cooled to 4.5 K. It is planned to launch SPICA into the sun-earth L2 libration halo orbit using H II-A rocket in the middle of the 2010s and execute infrared observations at wavelengths mainly between 5 and 200 micron. The SPICA mission gives us a unique opportunity for coronagraph observations, because of the large telescope aperture, the simple pupil shape, the capability of infrared observations from space, and the early launch. We have started development of the SPICA coronagraph in which the primary target is direct observation of extra-solar Jovian planets. The main wavelengths of observation, the required contrast and the inner working angle (IWA) of the SPICA coronagraph instrument are set to be 5-27 micron, 10^-6, and a few λ/D (and as small as possible), respectively, in which λ is the observation wavelength and D is the diameter of the telescope aperture (3.5m). We focused on a coronagraph with a binary shaped pupil mask as the primary candidate for SPICA because of its feasibility. Nano-fabrication technology using electron beam lithography was applied to manufacture a high precision mask and a laboratory experiment with a He-Ne laser (λ=632.8nm) was performed in air without active wavefront control. The raw contrast derived from the average measured in the dark region reached 6.7×10^-8. On the other hand, a study of Phase Induced Amplitude Apodization (PIAA) was started in an attempt to achieve higher performance, i.e., smaller IWA and higher throughput. A hybrid solution using PIAA and a shaped pupil mask was proposed. A laboratory experiment was performed using a He- Ne laser with active wavefront control via a 32×32 channel deformable mirror. A raw contrast of 6.5×10^-7 was achieved. Designs of binary shaped pupil mask are presented for the actual SPICA pupil which is obstructed by the telescope's secondary mirror and its support. Subtraction of point spread function (PSF) was also evaluated.

Proceedings Article | 7 July 2006 Paper

Paper

Development of an MIR coronagraph for the SPICA mission

Keigo Enya, Shinichiro Tanaka, Takao Nakagawa, Hirokazu Kataza, Lyu Abe, Motohide Tamura, Jun Nishikawa, Naoshi Murakami, Kenta Fujita, Yoich Itoh

Proceedings Volume 6265, 626536 (2006) https://doi.org/10.1117/12.670976

KEYWORDS: Coronagraphy, Space telescopes, Telescopes, Infrared telescopes, Mirrors, Point spread functions, Mid-IR, Infrared radiation, Planets, Binary data

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Proceedings Article | 28 June 2006 Paper

Paper

Concept and science of HiCIAO: high contrast instrument for the Subaru next generation adaptive optics

Motohide Tamura, Klaus Hodapp, Hideki Takami, Lyu Abe, Hiroshi Suto, Olivier Guyon, Shane Jacobson, Ryo Kandori, Jun-Ichi Morino, Naoshi Murakami, Vern Stahlberger, Ryuji Suzuki, Alexander Tavrov, Hubert Yamada, Jun Nishikawa, Nobuharu Ukita, Jun Hashimoto, Hideyuki Izumiura, Masahiko Hayashi, Tadashi Nakajima, Tetsuo Nishimura

Proceedings Volume 6269, 62690V (2006) https://doi.org/10.1117/12.670742

KEYWORDS: Coronagraphy, Adaptive optics, Stars, Telescopes, Exoplanets, Polarization, Astronomy, Optical filters, Space telescopes, Actuators

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Proceedings Article | 28 June 2006 Paper

Paper

Removal of central obscuration and spiders for coronagraphy

L. Abe, J. Nishikawa, N. Murakami, M. Tamura

Proceedings Volume 6269, 626950 (2006) https://doi.org/10.1117/12.670953

KEYWORDS: Coronagraphy, Beam shaping, Telescopes, Optical filters, Adaptive optics, Apodization, Fourier transforms, Phase shifts, Astronomy, Observatories

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Proceedings Article | 23 June 2006 Paper

Paper

MIRA status report: recent progress of MIRA-I.2 and future plans

Masanori Yoshizawa, Jun Nishikawa, Naoko Ohishi, Shunsaku Suzuki, Yasuo Torii, Hikaru Iwashita, Kohichi Kubo, Ko Matsuda, Naoshi Murakami, Akihisa Matsukawa, Takeshi Nishimura, Noriaki Okayasu, Sho Watanabe

Proceedings Volume 6268, 626808 (2006) https://doi.org/10.1117/12.671109

KEYWORDS: Stars, Visibility, Interferometers, Modulation, Ferroelectric materials, Mirrors, Imaging arrays, Fringe analysis, Astronomy, Observatories

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Proceedings Article | 15 June 2006 Paper

Paper

Nulling and adaptive optics for very high dynamic range coronagraph

Jun Nishikawa, Naoshi Murakami, Lyu Abe, Takayuki Kotani, Motohide Tamura, Kaito Yokochi, Takashi Kurokawa

Proceedings Volume 6265, 62653Q (2006) https://doi.org/10.1117/12.671541

KEYWORDS: Coronagraphy, Wavefronts, Interferometers, Nulling interferometry, Adaptive optics, Telescopes, High dynamic range imaging, Beam splitters, Picture Archiving and Communication System, Deformable mirrors

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Proceedings Article | 15 June 2006 Paper

Paper

Polarization and spectral differential imager using channeled spectrum

Naoshi Murakami, Naoshi Baba

Proceedings Volume 6265, 62653T (2006) https://doi.org/10.1117/12.669626

KEYWORDS: Polarization, Imaging systems, Wave plates, Polarizers, Modulation, Bandpass filters, Exoplanets, Interference filters, Speckle, Prisms

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Proceedings Article | 31 August 2005 Paper

Paper

Objective spectrometer for exoplanets based on nulling polarization interferometry

Naoshi Baba, Naoshi Murakami, Youko Tate, Yoichiro Sato, Motohide Tamura

Proceedings Volume 5905, 590512 (2005) https://doi.org/10.1117/12.615623

KEYWORDS: Exoplanets, Polarization, Spectroscopy, Coronagraphy, Lamps, Wave plates, Speckle, Interferometry, Halogens, Polarizers

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Proceedings Article | 12 October 2004 Paper

Paper

Two-channel polarization interferometric coronagraph to improve the detectability of extrasolar planets

Naoshi Murakami, Tasuku Maeda, Naoshi Baba, Tsuyoshi Ishigaki, Nobuyuki Hashimoto, Motohide Tamura

Proceedings Volume 5487, (2004) https://doi.org/10.1117/12.549548

KEYWORDS: Coronagraphy, Planets, Polarization, Exoplanets, Polarizers, Interferometry, Stars, Beam splitters, Lamps, Signal to noise ratio

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Proceedings Article | 3 March 2003 Paper

Paper

Nulling stellar coronagraph using liquid-crystal device

Naoshi Murakami, Naoshi Baba, Tsuyoshi Ishigaki, Nobuyuki Hashimoto

Proceedings Volume 4860, (2003) https://doi.org/10.1117/12.457651

KEYWORDS: Polarization, Polarizers, Liquid crystals, Phase shifts, Coronagraphy, Light sources, Stars, Nulling interferometry, Molecules, Exoplanets

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Proceedings Article | 21 February 2003 Paper

Paper

Nulling interferometer with geometric phase modulator

Naoshi Baba, Naoshi Murakami, Tsuyoshi Ishigaki

Proceedings Volume 4838, (2003) https://doi.org/10.1117/12.458082

KEYWORDS: Polarization, Interferometers, Modulators, Phase shift keying, Phase shifts, Nulling interferometry, Stars, Planets, Lamps, Polarizers

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Showing 5 of 52 publications

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