Dr. Tomohiko Nakamura Profile

Dr. Tomohiko Nakamura

SPIE Involvement:

Author

Publications (21)

Proceedings Article | 9 August 2016 Paper

A method for reducing atmospheric noise without chopping for ground-based mid-infrared observations

Tomohiko Nakamura, Takashi Miyata, Shigeyuki Sako, Takafumi Kamizuka, Kentaro Asano, Mizuho Uchiyama, Kazushi Okada

Proceedings Volume 9908, 99082U (2016) https://doi.org/10.1117/12.2231996

KEYWORDS: Mid-IR, Atmospheric turbulence, Superposition, Telescopes, Sensors, Image processing, Switching, Photometry, Astronomy, Image quality

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Proceedings Article | 28 July 2014 Paper

Development of high-throughput silicon lens and grism with moth-eye anti-reflection structure

Takafumi Kamizuka, Takashi Miyata, Shigeyuki Sako, Hiroaki Imada, Ryou Ohsawa, Kentaro Asano, Mizuho Uchiyama, Kazushi Okada, Masahito Uchiyama, Takehiko Wada, Takao Nakagawa, Tomohiko Nakamura, Itsuki Sakon, Takashi Onaka

Proceedings Volume 9151, 91515G (2014) https://doi.org/10.1117/12.2055756

KEYWORDS: Antireflective coatings, Silicon, Coating, Transmittance, Mid-IR, Signal detection, Imaging systems, Astronomy, Cryogenics, Lithography

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Proceedings Article | 18 July 2014 Paper

Restraint deformation and corrosion protection of gold deposited aluminum mirrors for cold optics of mid-infrared instruments

Mizuho Uchiyama, Takashi Miyata, Shigeyuki Sako, Takafumi Kamizuka, Tomohiko Nakamura, Kentaro Asano, Kazushi Okada, Takashi Onaka, Itsuki Sakon, Hirokazu Kataza, Yuki Sarugaku, Okiharu Kirino, Hiroyuki Nakagawa, Norio Okada, Kenji Mitsui

Proceedings Volume 9151, 915143 (2014) https://doi.org/10.1117/12.2054917

KEYWORDS: Mirrors, Aluminum, Corrosion, Gold, Mid-IR, Temperature metrology, Reflectivity, Photovoltaics, Coating, Astronomy

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Proceedings Article | 8 July 2014 Paper

Revised specifications and current development status of MIMIZUKU: the mid-infrared instrument for the TAO 6.5-m telescope

Takafumi Kamizuka, Takashi Miyata, Shigeyuki Sako, Ryou Ohsawa, Kentaro Asano, Mizuho Uchiyama, Kazushi Okada, Masahito Uchiyama, Tomohiko Nakamura, Itsuki Sakon, Takashi Onaka, Hirokazu Kataza, Tsutomu Aoki, Mamoru Doi, Natsuko Kato, Kimiaki Kawara, Yutaro Kitagawa, Kotaro Kohno, Masahiro Konishi, Shintaro Koshida, Takeo Minezaki, Tomoki Morokuma, Kentaro Motohara, Takao Soyano, Hidenori Takahashi, Yoichi Tamura, Toshihiko Tanabé, Masuo Tanaka, Ken'ichi Tarusawa, Ken Tateuchi, Soya Todo, Yuzuru Yoshii

Proceedings Volume 9147, 91473C (2014) https://doi.org/10.1117/12.2056184

KEYWORDS: Telescopes, Cameras, Mid-IR, Sensors, Mirrors, Near infrared, Spectroscopy, Space telescopes, Stars, Calibration

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Proceedings Article | 24 September 2012 Paper

Development of a new calibration method for ground-based Paschen-alpha imaging data

Ken Tateuchi, Kentaro Motohara, Masahiro Konishi, Hidenori Takahashi, Natsuko Kato, Ryou Ohsawa, Kitagawa Yutaro, Yuzuru Yoshii, Mamoru Doi, Toshihiro Handa, Kotaro Kohno, Kimiaki Kawara, Masuo Tanaka, Takashi Miyata, Takeo Minezaki, Shigeyuki Sako, Toshihiko Tanabe, Tomoki Morokuma, Yoichi Tamura, Tsutomu Aoki, Takao Soyano, Ken'ichi Tarusawa, Shintaro Koshida, Takafumi Kamizuka, Tomohiko Nakamura, Kentaro Asano, Mizuho Uchiyama

Proceedings Volume 8446, 84467D (2012) https://doi.org/10.1117/12.924263

KEYWORDS: Absorption, Transmittance, Atmospheric modeling, Galactic astronomy, Calibration, Protactinium, Infrared radiation, Near infrared, Cameras, Telescopes

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Proceedings Article | 24 September 2012 Paper

Development of MIMIZUKU: a mid-infrared multi-field imager for 6.5-m TAO telescope

Takafumi Kamizuka, Takashi Miyata, Shigeyuki Sako, Tomohiko Nakamura, Kentaro Asano, Mizuho Uchiyama, Kazushi Okada, Takashi Onaka, Itsuki Sakon, Hirokazu Kataza, Yuki Sarugaku, Yuzuru Yoshii, Mamoru Doi, Kotaro Kohno, Kimiaki Kawara, Masuo Tanaka, Kentaro Motohara, Toshihiko Tanabe, Takeo Minezaki, Tomoki Morokuma, Yoichi Tamura, Tsutomu Aoki, Takao Soyano, Ken'ichi Tarusawa, Natsuko Kato, Masahiro Konishi, Hidenori Takahashi, Shintaro Koshida, Ken Tateuchi, Toshihiro Handa

Proceedings Volume 8446, 84466P (2012) https://doi.org/10.1117/12.926771

KEYWORDS: Mirrors, Sensors, Telescopes, Near infrared, Imaging systems, Mid-IR, Cryogenics, Astronomy, Spectroscopy, Space telescopes

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Proceedings Article | 24 September 2012 Paper

Perfomance verification of the ground-based mid-infrared camera MAX38 on the MiniTAO Telescope

Kentaro Asano, Takashi Miyata, Shigeyuki Sako, Takafumi Kamizuka, Tomohiko Nakamura, Mizuho Uchiyama, Mizuki Yoneda, Hirokazu Kataza, Yuzuru Yoshii, Mamoru Doi, Kotaro Kohno, Kimiaki Kawara, Masuo Tanaka, Kentaro Motohara, Toshihiko Tanabe, Takeo Minezaki, Tomoki Morokuma, Yoichi Tamura, Tsutomu Aoki, Takao Soyano, Ken'ichi Tarusawa, Natsuko Kato, Masahiro Konishi, Shintaro Koshida, Hidenori Takahashi, Toshihiro Handa, Ken Tateuchi

Proceedings Volume 8446, 844634 (2012) https://doi.org/10.1117/12.925590

KEYWORDS: Stars, Telescopes, Mid-IR, Astronomy, Spatial resolution, Point spread functions, Cameras, Diffraction, Asteroids, Space telescopes

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Proceedings Article | 21 September 2012 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 | 17 September 2012 Paper

Evaluations of new atmospheric windows at thirty micron wavelengths for astronomy

Takashi Miyata, Shigeyuki Sako, Takafumi Kamizuka, Tomohiko Nakamura, Kentaro Asano, Mizuho Uchiyama, Masahiro Konishi, Mizuki Yoneda, Naruhisa Takato, Yuzuru Yoshii, Mamoru Doi, Kotaro Kohno, Kimiaki Kawara, Masuo Tanaka, Kentaro Motohara, Takeo Minezaki, Toshihiko Tanabe, Tomoki Morokuma, Yoichi Tamura, Tsutomu Aoki, Takao Soyano, Ken'ichi Tarusawa, Hidenori Takahashi, Shintaro Koshida, Natsuko Kato

Proceedings Volume 8444, 84446B (2012) https://doi.org/10.1117/12.925258

KEYWORDS: Transmittance, Astronomy, Telescopes, Stars, Atmospheric modeling, Mid-IR, Liquids, Optical filters, Cameras, Sensors

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Proceedings Article | 13 September 2012 Paper

Fabrication and tolerances of moth-eye structures for perfect antireflection in the mid-infrared wavelength region

Hiroaki Imada, Takashi Miyata, Shigeyuki Sako, Takafumi Kamizuka, Tomohiko Nakamura, Kentaro Asano, Mizuho Uchiyama, Kazushi Okada, Takehiko Wada, Takao Nakagawa, Takashi Onaka, Itsuki Sakon

Proceedings Volume 8450, 84502F (2012) https://doi.org/10.1117/12.925762

KEYWORDS: Antireflective coatings, Transmittance, Silicon, Mid-IR, Refractive index, Tolerancing, Astronomy, Scanning electron microscopy, Absorption, Solids

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Proceedings Article | 13 September 2012 Paper

Development of high-throughput silicon lens and grism with moth-eye antireflection structure for mid-infrared astronomy

Takafumi Kamizuka, Takashi Miyata, Shigeyuki Sako, Hiroaki Imada, Tomohiko Nakamura, Kentaro Asano, Mizuho Uchiyama, Kazushi Okada, Takehiko Wada, Takao Nakagawa, Takashi Onaka, Itsuki Sakon

Proceedings Volume 8450, 845051 (2012) https://doi.org/10.1117/12.926858

KEYWORDS: Antireflective coatings, Silicon, Coating, Photomasks, Transmittance, Semiconducting wafers, Astronomy, Refractive index, Mid-IR, Optical components

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Proceedings Article | 13 September 2012 Paper

Developing metal coated mesh filters for mid-infrared astronomy

Shigeyuki Sako, Takashi Miyata, Takafumi Kamizuka, Tomohiko Nakamura, Kentaro Asano, Mizuho Uchiyama, Takashi Onaka, Itsuki Sakon, Takehiko Wada

Proceedings Volume 8450, 84503V (2012) https://doi.org/10.1117/12.925768

KEYWORDS: Optical filters, Metals, Gold, Astronomy, Silicon carbide, Mid-IR, Temperature metrology, Finite-difference time-domain method, Semiconducting wafers, Bandpass filters

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Proceedings Article | 24 January 2011 Paper

Cubic III-nitrides: potential photonic materials

K. Onabe, S. Sanorpim, H. Kato, M. Kakuda, T. Nakamura, K. Nakamura, S. Kuboya, R. Katayama

Proceedings Volume 7945, 794517 (2011) https://doi.org/10.1117/12.865768

KEYWORDS: Gallium nitride, Aluminum, Gallium arsenide, Silicon, Gallium, Diffraction, Doping, Luminescence, Indium nitride, Optical properties

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Proceedings Article | 21 July 2010 Paper

MiniTAO/MAX38 first light: 30-micron band observations from the ground-based telescope

Tomohiko Nakamura, Takashi Miyata, Shigeyuki Sako, Kentaro Asano, Mizuho Uchiyama, Toshihiko Tanabe, Mizuki Yoneda, Yoshifusa Ita, Takashi Onaka, Hirokazu Kataza, Tsutomu Aoki, Mamoru Doi, Toshihiro Handa, Daisuke Kato, Kimiaki Kawara, Kotaro Kohno, Masahiro Konishi, Shintaro Koshida, Takeo Minezaki, Natsuko Mitani, Kentaro Motohara, Ryo Ohsawa, Takao Soyano, Masuo Tanaka, Ken'ichi Tarusawa, Koji Toshikawa, Yuzuru Yoshii

Proceedings Volume 7735, 773561 (2010) https://doi.org/10.1117/12.856228

KEYWORDS: Telescopes, Space telescopes, Transmittance, Mid-IR, Astronomy, Ferroelectric materials, Astronomical telescopes, Sensors, Spectroscopy, Optical filtering

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Proceedings Article | 20 July 2010 Paper

Development of a new mid-infrared instrument for the TAO 6.5-m Telescope

Takashi Miyata, Shigeyuki Sako, Tomohiko Nakamura, Kentaro Asano, Mizuho Uchiyama, Takashi Onaka, Itsuki Sakon, Hirokazu Kataza, Yoshifusa Ita, Tsutomu Aoki, Mamoru Doi, Toshihiro Handa, Daisuke Kato, Kimiaki Kawara, Kotaro Kohno, Masahiro Konishi, Shintaro Koshida, Takeo Minezaki, Natsuko Mitani, Kentaro Motohara, Takao Soyano, Toshihiko Tanabe, Masuo Tanaka, Ken'ichi Tarusawa, Yuzuru Yoshii

Proceedings Volume 7735, 77353P (2010) https://doi.org/10.1117/12.856744

KEYWORDS: Mid-IR, Telescopes, Space telescopes, Cameras, Sensors, Mirrors, Spatial resolution, Astronomy, Photometry, Stars

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Proceedings Article | 20 July 2010 Paper

First Paschen alpha imaging from the ground: the first light of Atacama Near-Infrared Camera on the miniTAO 1m telescope

Kentaro Motohara, Masahiro Konishi, Koji Toshikawa, Natsuko Mitani, Shigeyuki Sako, Yuka Uchimoto, Tomoyasu Yamamuro, Takeo Minezaki, Toshihiko Tanabe, Takashi Miyata, Shintaro Koshida, Daisuke Kato, Ryo Ohsawa, Tomohiko Nakamura, Kentaro Asano, Yuzuru Yoshii, Mamoru Doi, Kotaro Kohno, Masuo Tanaka, Kimiaki Kawara, Toshihiro Handa, Tsutomu Aoki, Takao Soyano, Ken'ichi Tarusawa, Yoshifusa Ita

Proceedings Volume 7735, 77353K (2010) https://doi.org/10.1117/12.856102

KEYWORDS: Telescopes, Protactinium, Transmittance, Near infrared, Cameras, Mirrors, Optical filters, Space telescopes, Astronomy, Device simulation

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Proceedings Article | 25 July 2008 Paper

Cold chopper system for mid-infrared instruments

Tomohiko Nakamura, Takashi Miyata, Shigeyuki Sako, Takashi Onaka, Keigo Enya, Hirokazu Kataza, Hidenori Takahashi, Yoshiyuki Obuchi

Proceedings Volume 7018, 70184H (2008) https://doi.org/10.1117/12.787762

KEYWORDS: Mirrors, Ferroelectric materials, Telescopes, Sensors, Space telescopes, Mid-IR, Actuators, Atmospheric turbulence, Astronomy, Observatories

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Proceedings Article | 23 July 2008 Paper

Developing metal mesh filters for mid-infrared astronomy of 25 to 40 micron

Shigeyuki Sako, Takashi Miyata, Tomohiko Nakamura, Takashi Onaka, Yuji Ikeda, Hirokazu Kataza

Proceedings Volume 7018, 701853 (2008) https://doi.org/10.1117/12.788510

KEYWORDS: Transmittance, Finite-difference time-domain method, Metals, Refractive index, Astronomy, Mid-IR, Bandpass filters, Optical filters, Space telescopes, Silicon

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Proceedings Article | 22 July 2008 Paper

Developing infrared array controller with software real time operating system

Shigeyuki Sako, Takashi Miyata, Tomohiko Nakamura, Kentaro Motohara, Yuka Katsuno Uchimoto, Takashi Onaka, Hirokazu Kataza

Proceedings Volume 7021, 702128 (2008) https://doi.org/10.1117/12.788633

KEYWORDS: Clocks, Fiber reinforced polymers, Digital signal processing, Signal processing, Infrared radiation, Operating systems, Data processing, Control systems, Field programmable gate arrays, Cameras

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Proceedings Article | 12 July 2008 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 | 9 July 2008 Paper

A new mid-infrared camera for ground-based 30 micron observations: MAX38

Takashi Miyata, Shigeyuki Sako, Tomohiko Nakamura, Takashi Onaka, Hirokazu Kataza

Proceedings Volume 7014, 701428 (2008) https://doi.org/10.1117/12.787739

KEYWORDS: Telescopes, Mid-IR, Sensors, Mirrors, Astronomy, Space telescopes, Cameras, Infrared telescopes, Detector arrays, Imaging spectroscopy

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Showing 5 of 21 publications

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