Dr. Hajime Kawahara Profile

Dr. Hajime Kawahara

at Univ of Tokyo

SPIE Involvement:

Author

Publications (17)

Proceedings Article | 1 September 2021 Presentation + Paper

Presentation + Paper

SCExAO: a testbed for developing high-contrast imaging technologies for ELTs

Kyohoon Ahn, Olivier Guyon, Julien Lozi, Sébastien Vievard, Vincent Deo, Nour Skaf, Ruslan Belikov, Steven Bos, Michael Bottom, Thayne Currie, Richard Frazin, Kyle V. Gorkom, Tyler Groff, Sebastiaan Haffert, Nemanja Jovanovic, Hajime Kawahara, Takayuki Kotani, Jared Males, Frantz Martinache, Ben Mazin, Kelsey Miller, Barnaby Norris, Alexander Rodack, Alison Wong

Proceedings Volume 11823, 1182303 (2021) https://doi.org/10.1117/12.2594963

KEYWORDS: Coronagraphy, Telescopes, Human-computer interaction, Speckle, Stars, Adaptive optics, Visible radiation, Exoplanets, Wavefronts, Wavefront sensors

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Proceedings Article | 21 December 2020 Poster + Paper

Poster + Paper

Extremely high-contrast, high spectral resolution spectrometer REACH for the Subaru Telescope

T. Kotani, H. Kawahara, M. Ishizuka, N. Jovanovic, S. Vievard, J. Lozi, A. Sahoo, O. Guyon, K. Yoneta, M. Tamura

Proceedings Volume 11448, 1144878 (2020) https://doi.org/10.1117/12.2561755

KEYWORDS: Spectral resolution, Telescopes, Single mode fibers, Adaptive optics, Speckle, Spectrographs, Atmospheric optics, Infrared telescopes, Coronagraphy, Near infrared

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Proceedings Article | 13 December 2020 Presentation + Paper

Presentation + Paper

LOTUS: wide-field monitoring nanosatellite for finding long-period transiting planets

Hajime Kawahara, Kento Masuda, Takayuki Kotani, Shotaro Tada, Hirokazu Kataza, Satoshi Ikari, Hiroki Aohama, Takayuki Hosonuma, Wataru Mikuriya, Masahiro Ikoma, Satoshi Kasahara, Shigeyuki Sako, Seiji Sugita, Eri Tatsumi, Kazuo Yoshioka

Proceedings Volume 11443, 1144316 (2020) https://doi.org/10.1117/12.2562266

KEYWORDS: Planets, Exoplanets, Cameras, Optical design, Sensors, Space operations, Point spread functions, Photometry, Cooling systems

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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 | 13 December 2020 Presentation + Paper

Presentation + Paper

Constraining orbits and masses of stellar companions with SCExAO imaging and REACH spectroscopy

Ananya Sahoo, Julien Lozi, Sebastien Vievard, Olivier Guyon, Takayuki Kotani, Hajime Kawahara, Nemanja Jovanovic, Vincent Deo, Masato Ishizuka

Proceedings Volume 11448, 1144809 (2020) https://doi.org/10.1117/12.2563133

KEYWORDS: Stars, Imaging systems, Satellite imaging, Satellites, Deformable mirrors, Modulation, Atmospheric optics, Imaging spectroscopy, Velocity measurements, Spectroscopy

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Proceedings Article | 13 December 2020 Presentation + Paper

Presentation + Paper

Validating advanced wavefront control techniques on the SCExAO testbed/instrument

Olivier Guyon, Julien Lozi, Sebastien Vievard, Ruslan Belikov, Eduardo Bendek, Steven Bos, Thayne Currie, Vincent Deo, Michael Fitzgerald, Damien Gratadour, Tyler Groff, Nemanja Jovanovic, Hajime Kawahara, Takayuki Kotani, Tomoyuki Kudo, Coline Lopez, Hatem Ltaief, Jared Males, Frantz Martinache, Marc-Antoine Martinod, Benjamin Mazin, Kelsey Miller, Barnaby Norris, Mamadou Ndiaye, Eugene Pluzhnyk, Ananya Sahoo, Arnaud Sevin, Nour Skaf, Frans Snik, Motohide Tamura, Alison Wong

Proceedings Volume 11448, 114481Z (2020) https://doi.org/10.1117/12.2562723

KEYWORDS: Wavefronts, Adaptive optics, Coronagraphy, Prototyping, Sensor fusion, Cameras, Hardware testing, Multiplexing, Wavefront sensors, Reliability

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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 July 2018 Paper

Paper

SCExAO, an instrument with a dual purpose: perform cutting-edge science and develop new technologies

Julien Lozi, Olivier Guyon, Nemanja Jovanovic, Sean Goebel, Prashant Pathak, Nour Skaf, Ananya Sahoo, Barnaby Norris, Frantz Martinache, Mamadou N'Diaye, Ben Mazin, Alex Walter, Peter Tuthill, Tomoyuki Kudo, Hajime Kawahara, Takayuki Kotani, Michael Ireland, Nick Cvetojevic, Elsa Huby, Sylvestre Lacour, Sébastien Vievard, Tyler Groff, Jeffrey Chilcote, Jeremy Kasdin, Justin Knight, Frans Snik, David Doelman, Yosuke Minowa, Christophe Clergeon, Naruhisa Takato, Motohide Tamura, Thayne Currie, Hideki Takami, Masa Hayashi

Proceedings Volume 10703, 1070359 (2018) https://doi.org/10.1117/12.2314282

KEYWORDS: Cameras, Coronagraphy, Polarization, Near infrared, Speckle, Exoplanets, Wavefronts, Telescopes, Infrared radiation, Polarimetry

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Proceedings Article | 13 July 2018 Paper

Paper

The infrared Doppler (IRD) instrument for the Subaru telescope: instrument description and commissioning results

Takayuki Kotani, Motohide Tamura, Jun Nishikawa, Akitoshi Ueda, Masayuki Kuzuhara, Masashi Omiya, Jun Hashimoto, Masato Ishizuka, Teruyuki Hirano, Hiroshi Suto, Takashi Kurokawa, Tsukasa Kokubo, Takahiro Mori, Yosuke Tanaka, Ken Kashiwagi, Mihoko Konishi, Tomoyuki Kudo, Bun'ei Sato, Shane Jacobson, Klaus Hodapp, Donald Hall, Wako Aoki, Tomonori Usuda, Shogo Nishiyama, Tadashi Nakajima, Yuji Ikeda, Tomoyasu Yamamuro, Jun-Ichi Morino, Haruka Baba, Ko Hosokawa, Hiroyuki Ishikawa, Norio Narita, Eiichiro Kokubo, Yutaka Hayano, Hideyuki Izumiura, Eiji Kambe, Nobuhiko Kusakabe, Jungmi Kwon, Masahiro Ikoma, Yasunori Hori, Hidenori Genda, Akihiko Fukui, Yuka Fujii, Hajime Kawahara, Guyon Olivier, Nemanja Jovanovic, Hiroki Harakawa, Masahiko Hayashi, Masahide Hidai, Masahiro Machida, Taro Matsuo, Tetsuya Nagata, Masahiro Ogihara, Hideki Takami, Naruhisa Takato, Hiroshi Terada, Daehyeon Oh

Proceedings Volume 10702, 1070211 (2018) https://doi.org/10.1117/12.2311836

KEYWORDS: Stars, Spectroscopy, Telescopes, Sensors, Cameras, Error analysis, Mirrors, Infrared telescopes, Frequency combs, Adaptive optics

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Proceedings Article | 26 July 2016 Paper

Paper

The SCExAO high contrast imager: transitioning from commissioning to science

N. Jovanovic, O. Guyon, J. Lozi, T. Currie, J. Hagelberg, B. Norris, G. Singh, P. Pathak, D. Doughty, S. Goebel, J. Males, J. Kuhn, E. Serabyn, P. Tuthill, G. Schworer, F. Martinache, T. Kudo, H. Kawahara, T. Kotani, M. Ireland, T. Feger, A. Rains, J. Bento, C. Schwab, D. Coutts, N. Cvetojevic, S. Gross, A. Arriola, T. Lagadec, J. Kasdin, T. Groff, B. Mazin, Y. Minowa, N. Takato, M. Tamura, H. Takami, M. Hayashi

Proceedings Volume 9909, 99090W (2016) https://doi.org/10.1117/12.2234294

KEYWORDS: Adaptive optics, Imaging systems, Stars, Telescopes, Calibration, Visible radiation, Spectrographs, Speckle, Cameras, Prisms

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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 | 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 | 14 July 2014 Paper

Paper

Infrared Doppler instrument (IRD) for the Subaru telescope to search for Earth-like planets around nearby M-dwarfs

Takayuki Kotani, Motohide Tamura, Hiroshi Suto, Jun Nishikawa, Bun'ei Sato, Wako Aoki, Tomonori Usuda, Takashi Kurokawa, Ken Kashiwagi, Shogo Nishiyama, Yuji Ikeda, Donald Hall, Klaus Hodapp, Jun Hashimoto, Jun-Ichi Morino, Yasushi Okuyama, Yosuke Tanaka, Shota Suzuki, Sadahiro Inoue, Jungmi Kwon, Takuya Suenaga, Dehyun Oh, Haruka Baba, Norio Narita, Eiichiro Kokubo, Yutaka Hayano, Hideyuki Izumiura, Eiji Kambe, Tomoyuki Kudo, Nobuhiko Kusakabe, Masahiro Ikoma, Yasunori Hori, Masashi Omiya, Hidenori Genda, Akihiko Fukui, Yuka Fujii, Olivier Guyon, Hiroki Harakawa, Masahiko Hayashi, Masahide Hidai, Teruyuki Hirano, Masayuki Kuzuhara, Masahiro Machida, Taro Matsuo, Tetsuya Nagata, Hirohi Onuki, Masahiro Ogihara, Hideki Takami, Naruhisa Takato, Yasuhiro Takahashi, Chihiro Tachinami, Hiroshi Terada, Hajime Kawahara, Tomoyasu Yamamuro

Proceedings Volume 9147, 914714 (2014) https://doi.org/10.1117/12.2055075

KEYWORDS: Stars, Optical fibers, Planets, Spectroscopy, Adaptive optics, Optical benches, Frequency combs, Sensors, Infrared telescopes, Ceramics

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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 | 17 September 2012 Paper

Paper

The ASTRO-H X-ray Observatory

Tadayuki Takahashi, Kazuhisa Mitsuda, Richard Kelley, Henri Aarts, Felix Aharonian, Hiroki Akamatsu, Fumie Akimoto, Steve Allen, Naohisa Anabuki, Lorella Angelini, Keith Arnaud, Makoto Asai, Marc Audard, Hisamitsu Awaki, Philipp Azzarello, Chris Baluta, Aya Bamba, Nobutaka Bando, Mark Bautz, Roger Blandford, Kevin Boyce, Greg Brown, Ed Cackett, Mara Chernyakova, Paolo Coppi, Elisa Costantini, Jelle de Plaa, Jan-Willem den Herder, Michael DiPirro, Chris Done, Tadayasu Dotani, John Doty, Ken Ebisawa, Megan Eckart, Teruaki Enoto, Yuichiro Ezoe, Andrew Fabian, Carlo Ferrigno, Adam Foster, Ryuichi Fujimoto, Yasushi Fukazawa, Stefan Funk, Akihiro Furuzawa, Massimiliano Galeazzi, Luigi Gallo, Poshak Gandhi, Keith Gendreau, Kirk Gilmore, Daniel Haas, Yoshito Haba, Kenji Hamaguchi, Isamu Hatsukade, Takayuki Hayashi, Kiyoshi Hayashida, Junko Hiraga, Kazuyuki Hirose, Ann Hornschemeier, Akio Hoshino, John Hughes, Una Hwang, Ryo Iizuka, Yoshiyuki Inoue, Kazunori Ishibashi, Manabu Ishida, Kosei Ishimura, Yoshitaka Ishisaki, Masayuki Ito, Naoko Iwata, Naoko Iyomoto, Jelle Kaastra, Timothy Kallman, Tuneyoshi Kamae, Jun Kataoka, Satoru Katsuda, Hajime Kawahara, Madoka Kawaharada, Nobuyuki Kawai, Shigeo Kawasaki, Dmitry Khangaluyan, Caroline Kilbourne, Masashi Kimura, Kenzo Kinugasa, Shunji Kitamoto, Tetsu Kitayama, Takayoshi Kohmura, Motohide Kokubun, Tatsuro Kosaka, Alex Koujelev, Katsuji Koyama, Hans Krimm, Aya Kubota, Hideyo Kunieda, Stephanie LaMassa, Philippe Laurent, Francois Lebrun, Maurice Leutenegger, Olivier Limousin, Michael Loewenstein, Knox Long, David Lumb, Grzegorz Madejski, Yoshitomo Maeda, Kazuo Makishima, Genevieve Marchand, Maxim Markevitch, Hironori Matsumoto, Kyoko Matsushita, Dan McCammon, Brian McNamara, Jon Miller, Eric Miller, Shin Mineshige, Kenji Minesugi, Ikuyuki Mitsuishi, Takuya Miyazawa, Tsunefumi Mizuno, Hideyuki Mori, Koji Mori, Koji Mukai, Toshio Murakami, Hiroshi Murakami, Richard Mushotzky, Hosei Nagano, Ryo Nagino, Takao Nakagawa, Hiroshi Nakajima, Takeshi Nakamori, Kazuhiro Nakazawa, Yoshiharu Namba, Chikara Natsukari, Yusuke Nishioka, Masayoshi Nobukawa, Masaharu Nomachi, Steve O'Dell, Hirokazu Odaka, Hiroyuki Ogawa, Mina Ogawa, Keiji Ogi, Takaya Ohashi, Masanori Ohno, Masayuki Ohta, Takashi Okajima, Atsushi Okamoto, Tsuyoshi Okazaki, Naomi Ota, Masanobu Ozaki, Fritzs Paerels, Stéphane Paltani, Arvind Parmar, Robert Petre, Martin Pohl, F. Scott Porter, Brian Ramsey, Rubens Reis, Christopher Reynolds, Helen Russell, Samar Safi-Harb, Shin-ichiro Sakai, Hiroaki Sameshima, Jeremy Sanders, Goro Sato, Rie Sato, Yohichi Sato, Kosuke Sato, Makoto Sawada, Peter Serlemitsos, Hiromi Seta, Yasuko Shibano, Maki Shida, Takanobu Shimada, Keisuke Shinozaki, Peter Shirron, Aurora Simionescu, Cynthia Simmons, Randall Smith, Gary Sneiderman, Yang Soong, Lukasz Stawarz, Yasuharu Sugawara, Hiroyuki Sugita, Satoshi Sugita, Andrew Szymkowiak, Hiroyasu Tajima, Hiromitsu Takahashi, Shin-ichiro Takeda, Yoh Takei, Toru Tamagawa, Takayuki Tamura, Keisuke Tamura, Takaaki Tanaka, Yasuo Tanaka, Makoto Tashiro, Yuzuru Tawara, Yukikatsu Terada, Yuichi Terashima, Francesco Tombesi, Hiroshi Tomida, Yohko Tsuboi, Masahiro Tsujimoto, Hiroshi Tsunemi, Takeshi Tsuru, Hiroyuki Uchida, Yasunobu Uchiyama, Hideki Uchiyama, Yoshihiro Ueda, Shiro Ueno, Shinichiro Uno, Meg Urry, Eugenio Ursino, Cor de Vries, Atsushi Wada, Shin Watanabe, Norbert Werner, Nicholas White, Takahiro Yamada, Shinya Yamada, Hiroya Yamaguchi, Noriko Yamasaki, Shigeo Yamauchi, Makoto Yamauchi, Yoichi Yatsu, Daisuke Yonetoku, Atsumasa Yoshida, Takayuki Yuasa

Proceedings Volume 8443, 84431Z (2012) https://doi.org/10.1117/12.926190

KEYWORDS: Sensors, X-rays, Hard x-rays, X-ray telescopes, Physics, X-ray astronomy, Iron, Spectroscopy, X-ray imaging, Galaxy groups and clusters

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Showing 5 of 17 publications

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