Prof. Hiroshi Kumagai Profile

Prof. Hiroshi Kumagai

Prof. at Kitasato Univ

SPIE Involvement:

Author

Publications (57)

Proceedings Article | 4 March 2022 Presentation + Paper

Image analysis of erythema for quantitative evaluation of photosensitivity in photodynamic therapy

Hayato Ito, Sota Kawakami, Hiroshi Kumagai, Manabu Muto, Masahiro Yoshioka, Emiyu Ogawa

Proceedings Volume 11938, 1193803 (2022) https://doi.org/10.1117/12.2607546

KEYWORDS: Photodynamic therapy, Image analysis, RGB color model, Skin, Imaging systems, Tumors, Visualization, Oxygen, Oncology, Medicine

Read Abstract +

Proceedings Article | 5 March 2021 Poster + Presentation + Paper

Development of phase-locked loop high-frequency optically pumped atomic magnetometer module operating under unshielded condition

Shun Takeda, Hiroshi Kumagai, Satoru Nebuya

Proceedings Volume 11700, 1170047 (2021) https://doi.org/10.1117/12.2578034

KEYWORDS: Optical pumping, Magnetometers, Magnetism, Phase shift keying, Magnetic sensors, Vibration isolation, Spectroscopy, Modulation, Lung

Read Abstract +

Proceedings Article | 5 March 2021 Presentation + Paper

Intra-operative vascular monitoring during balloon angioplasty by vascular wall backscattering light measurement

Emiyu Ogawa, Tsunenori Arai, Hiroshi Kumagai

Proceedings Volume 11621, 116210G (2021) https://doi.org/10.1117/12.2577573

KEYWORDS: Optical testing, Backscatter, Scattering, Optical fibers, Laser therapeutics, Laser scattering, Laser irradiation, Laser development, Fiber lasers, Arteries

Read Abstract +

Proceedings Article | 5 March 2021 Presentation + Paper

HSP47 expression in fibroblasts by NIR laser irradiation in vitro

Sota Kawakami, Emiyu Ogawa, Hiroshi Kumagai

Proceedings Volume 11618, 1161806 (2021) https://doi.org/10.1117/12.2577466

KEYWORDS: Collagen, Laser irradiation, In vitro testing, Laser therapeutics, Skin, Pulsed laser operation, Photothermal effect, Finite element methods, Proteins, Optical simulations

Read Abstract +

Proceedings Article | 5 March 2021 Presentation + Paper

Room-temperature molecular layer deposition of inorganic-organic hybrid aluminum oxide thin films for preventing spin relaxation of cell inner wall of optically pumped atomic magnetometer

Hiroshi Kumagai, Shun Takeda, Ryo Yoshimitsu, Satoru Kobayashi, Haruki Ishikawa

Proceedings Volume 11675, 1167505 (2021) https://doi.org/10.1117/12.2579199

KEYWORDS: Thin films, Magnetometers, Optical pumping, Coating, Chemical species, Thin film coatings, Spin polarization, Rubidium, Deposition processes, Superconductors

Read Abstract +

Proceedings Article | 20 February 2020 Paper

Salted cadaver brain measurement for light attenuation of PDT

Emiyu Ogawa, Jiro Akimoto, Shinjiro Fukami, Tsunenori Arai, Hiroshi Kumagai

Proceedings Volume 11238, 112381I (2020) https://doi.org/10.1117/12.2551473

KEYWORDS: Brain, Signal attenuation, Photodynamic therapy, Tissue optics, Tissues, Optical testing, In situ metrology, Endoscopes, Sodium, Optical properties

Read Abstract +

Proceedings Article | 17 February 2020 Paper

Evaluation of a combined two-color phase plate forming three-dimensional dark holes in super resolution microscopy

Koumei Nagai, Takashi Maruyama, Akira Kodaira, Hiroshi Kumagai, Nándor Bokor, Yoshinori Iketaki

Proceedings Volume 11245, 1124518 (2020) https://doi.org/10.1117/12.2545877

KEYWORDS: Spiral phase plates, Luminescence, Super resolution, Etching, Super resolution microscopy, Objectives, Modulation, Optics manufacturing, Semiconductor manufacturing

Read Abstract +

Proceedings Article | 17 February 2020 Paper

Enhancement of Xe-NMR signals at low magnetic field using optical pumping hyperpolarization

Shun Takeda, Hiroshi Kumagai, Mineyuki Hattori

Proceedings Volume 11243, 112431W (2020) https://doi.org/10.1117/12.2544572

KEYWORDS: Xenon, Polarization, Magnetic resonance imaging, Rubidium, Optical pumping, Noble gases

Read Abstract +

Proceedings Article | 4 March 2019 Presentation + Paper

Preventing spin relaxation of optically pumped alkali metal atoms by atomically thin hybrid polymer film coating

H. Kumagai, S. Kobayashi, S. Takeda, E. Ogawa, H. Ishikawa

Proceedings Volume 10907, 109070Y (2019) https://doi.org/10.1117/12.2509254

KEYWORDS: Chemical species, Coating, Optical pumping, Polymer thin films, Atomic layer deposition, Spin polarization, Thin films, Magnetism, Rubidium, Alkali metals

Read Abstract +

Proceedings Article | 4 March 2019 Paper

Increase of NMR/MIR signals under ultra-low B fields with hyperpolarized Xe using 1W CW single-frequency Ti:Sapphire laser

Shun Takeda, Hiroshi Kumagai, Emiyu Ogawa, Mineyuki Hattori

Proceedings Volume 10881, 108811Q (2019) https://doi.org/10.1117/12.2508126

KEYWORDS: Xenon, Sapphire lasers, Rubidium, Electrons, Magnetic resonance imaging, High power lasers, Continuous wave operation, Noble gases, Optical pumping

Read Abstract +

Proceedings Article | 1 March 2019 Paper

Drug contact time dominates a necessary time for myocardial cells necrosis by a photodynamic reaction

Emiyu Ogawa, Yuiko Kikuchi, Hiroshi Kumagai, Tsunenori Arai

Proceedings Volume 10876, 1087602 (2019) https://doi.org/10.1117/12.2508112

KEYWORDS: Calcium, Luminescence, Microscopes, Confocal microscopy, Oxygen, Time metrology, Ions, Image analysis, Mathematical modeling

Read Abstract +

Proceedings Article | 24 April 2018 Paper

Observation of immunostained microtubules using three-dimensional super-resolution microscope with two-color annular wave plate

Yoshinori Iketaki, Nandor Bokor, Daisuke Okada, Hiroshi Kumagai

Proceedings Volume 10712, 1071203 (2018) https://doi.org/10.1117/12.2319154

KEYWORDS: Super resolution, Luminescence, Image resolution, 3D image processing, Diffraction, Wave plates, Microscopes, Super resolution microscopy, Beam shaping, Optical fibers

Read Abstract +

Proceedings Article | 20 February 2018 Paper

Improvement of spin-exchange optical pumping of xenon-129 using in situ NMR measurement in ultra-low magnetic field

Shun Takeda, Hiroshi Kumagai

Proceedings Volume 10497, 104971P (2018) https://doi.org/10.1117/12.2288669

KEYWORDS: Magnetism, Magnetic resonance imaging, Optical pumping, Xenon, Rubidium, Noble gases

Read Abstract +

Proceedings Article | 17 February 2017 Paper

Theoretical analysis of lateral resolution given by annular super-resolution phase plate

Hiroshi Kumagai, Yoshinori Iketaki, Koumei Nagai, Nador Bokor

Proceedings Volume 10070, 100701L (2017) https://doi.org/10.1117/12.2250814

KEYWORDS: Spiral phase plates, Luminescence, Spatial resolution, Super resolution, Microscopy, Quenching (fluorescence), Super resolution microscopy, Molecules, Diffraction, 3D modeling, Objectives, Physics, Gaussian beams

Read Abstract +

Proceedings Article | 16 February 2017 Paper

Laser polarized Xe NMR and MRI at ultra-low magnetic fields

Shun Takeda, Hiroshi Kumagai

Proceedings Volume 10068, 100681M (2017) https://doi.org/10.1117/12.2250804

KEYWORDS: Magnetic resonance imaging, Xenon, Magnetism, Optical pumping, Gas lasers, Gases, Functional imaging, Tomography, Chemical oxygen iodine lasers, Chemical species, Rubidium, Control systems, Inspection

Read Abstract +

Proceedings Article | 9 March 2016 Paper

Fabrication of two-color annular hybrid wave plate for three-dimensional super-resolution microscopy

Hiroshi Kumagai, Yoshinori Iketaki, Kornel Jahn, Nador Bokor

Proceedings Volume 9713, 971311 (2016) https://doi.org/10.1117/12.2211871

KEYWORDS: Luminescence, Beam shaping, Wave plates, Super resolution microscopy, Destructive interference, Microscopes, Microscopy, 3D scanning, Diffraction, Optical alignment, Super resolution, Quartz

Read Abstract +

Proceedings Article | 27 March 2013 Paper

Tunable picosecond THz-wave generation based on trapezoidal MgO:LiNbO3 crystal in novel pentagram-shaped pump-enhancement cavity

Yuma Takida, Yuzuru Tadokoro, Hiroshi Kumagai, Shigeki Nashima, Ataru Kobayashi

Proceedings Volume 8604, 86041F (2013) https://doi.org/10.1117/12.2001627

KEYWORDS: Terahertz radiation, Picosecond phenomena, Crystals, Mirrors, Polarization, Scattering, Absorption, Mode locking, Sapphire lasers, Laser scattering

Read Abstract +

Proceedings Article | 12 March 2013 Paper

Comparative study on THz time-domain spectroscopy using 780-nm 1.3-ps laser pulses with different detections of LT-GaAs photoconductive antenna and ZnTe electro-optic sampling

Yuzuru Tadokoro, Yuma Takida, Hiroshi Kumagai, Shigeki Nashima, Ataru Kobayashi

Proceedings Volume 8604, 86040D (2013) https://doi.org/10.1117/12.2001966

KEYWORDS: Terahertz radiation, Antennas, Principal component analysis, Crystals, Picosecond phenomena, Spectroscopy, Electro optics, Femtosecond phenomena, Mirrors, Polarization

Read Abstract +

Proceedings Article | 16 February 2012 Paper

Novel beam splitter for high-order harmonics with WO3/TiO2 bilayer grown on c-plane sapphire substrate by sequential surface chemical reactions

Yasutaka Sanjo, Masaki Murata, Hiroshi Kumagai, Yasuo Nabekawa, Katsumi Midorikawa, Masaya Chigane

Proceedings Volume 8245, 82450P (2012) https://doi.org/10.1117/12.909665

KEYWORDS: Reflectivity, Sapphire, Beam splitters, Chemical reactions, Silicon carbide, Reflection, Silicon, Synchrotron radiation, Oxygen, Titanium dioxide

Read Abstract +

Proceedings Article | 15 February 2012 Paper

Coherent electro-optical detection of THz-wave generated from synchronously pumped picosecond THz parametric oscillator

Yuma Takida, Tatsuya Ohira, Yuzuru Tadokoro, Hiroshi Kumagai, Shigeki Nashima

Proceedings Volume 8240, 82400A (2012) https://doi.org/10.1117/12.907824

KEYWORDS: Terahertz radiation, Picosecond phenomena, Antennas, Imaging spectroscopy, Silicon, Spectroscopy, Mirrors, Beam splitters, Sensors, Michelson interferometers

Read Abstract +

Proceedings Article | 15 February 2012 Paper

Sum-frequency generation of continuous-wave tunable ultraviolet coherent light in BBO-installed external cavity

Kenta Mukoyama, Kazuhiro Tokuyama, Hiroshi Kumagai, Norihiro Inoue, Naoaki Fukuda, Toshio Takiya

Proceedings Volume 8240, 82401J (2012) https://doi.org/10.1117/12.907849

KEYWORDS: Frequency conversion, Sum-frequency generation, Ultraviolet radiation, Nonlinear crystals, Mirrors, Crystals, Vacuum ultraviolet, Continuous wave operation, Second-harmonic generation, Actuators

Read Abstract +

Proceedings Article | 15 February 2012 Paper

Tunable terahertz parametric oscillator synchronously-pumped by mode-locked picosecond Ti:Sapphire laser with MgO-doped LiNbO3

Yuzuru Tadokoro, Yuma Takida, Tatsuya Ohira, Hiroshi Kumagai, Shigeki Nashima

Proceedings Volume 8240, 82401K (2012) https://doi.org/10.1117/12.907886

KEYWORDS: Terahertz radiation, Picosecond phenomena, Mode locking, Sapphire lasers, Crystals, Mirrors, Oscillators, Laser damage threshold, Imaging spectroscopy, Spectroscopy

Read Abstract +

Proceedings Article | 15 February 2012 Paper

Quasi phase matching through periodic step structure: modeling of frequency conversion in consideration of heat influence

Takafumi Ohfuchi, Nobuyuki Hirano, Hiroya Matsukawa, Koichiro Nakayama, Hiroshi Kumagai, Norihiro Inoue, Naoaki Fukuda, Toshio Takiya

Proceedings Volume 8240, 82401P (2012) https://doi.org/10.1117/12.909526

KEYWORDS: Crystals, Frequency conversion, Vacuum ultraviolet, Polarization, Laser crystals, Nonlinear crystals, Absorption, Refractive index, Quartz, Phase matching

Read Abstract +