Dr. Toshimasa Umezawa Profile

Dr. Toshimasa Umezawa

at NICT

SPIE Involvement:

Author

Publications (20)

Proceedings Article | 11 March 2024 Presentation + Paper

60-GHz low-phase noise optical-electrical oscillator using newly developed high-power photoreceiver module

T. Umezawa, Y. Yamaguchi, A. Matsumoto, A. Kanno, K. Akahane, N. Yamamoto

Proceedings Volume 12885, 128850E (2024) https://doi.org/10.1117/12.2691056

KEYWORDS: Oscillators, Modulators, Design, Photocurrent, Feedback loops, Telecommunications, Integrated optics, Signal attenuation, Optical modulators, Frequency response

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Proceedings Article | 18 March 2023 Presentation + Paper

Silica nanoparticles coating in silicon nitride photonic label-free biosensing of S100 calcium-binding protein A6

Suruk Udomsom, Phornsawat Baipaywad, Pathinan Paengnakorn, Ukrit Mankong, Nipon Theera-Umpon, Toshimasa Umezawa, Atsushi Matsumoto, Atsushi Kanno, Naokatsu Yamamoto, Kouichi Akahane, Manuel Mendez-Astudillo, Nithi Atthi, Wittawat Yamwong, Nipapan Klunngien, Rattanawan Meananeatra, Kitti Intuyod, Somchai Pinlaor, Tetsuya Kawanishi, Kazuo Imai

Proceedings Volume 12395, 1239502 (2023) https://doi.org/10.1117/12.2648777

KEYWORDS: Nanoparticles, Silica, Silicon nitride, Coating, Biosensing, Silicon photonics, Proteins, Antibodies, Biomedical optics, Waveguides

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Proceedings Article | 14 March 2023 Presentation

Fabrication of ultra-low-density InAs quantum dots on InP(311)B substrates for telecom-band single-photon sources (Conference Presentation)

Kouichi Akahane, Kiyora Kaneki, Atsushi Matsumoto, Toshimasa Umezawa, Naokatsu Yamamoto, Tomohiro Maeda, Hideyuki Sotobayashi, Yoriko Tominaga, Atsushi Kanno

Proceedings Volume 12417, 124170C (2023) https://doi.org/10.1117/12.2648147

KEYWORDS: Indium arsenide, Quantum dots, Chemical species, Quantum computing, Quantum communications, Bismuth, Telecommunications, Single photon, Semiconductors, Optical semiconductors

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Proceedings Article | 13 March 2023 Presentation

100 GHz optical-to-radio converter and its startup performance driven by power over fiber

Toshimasa Umezawa, Atsushi Matsumoto, Kouichi Akahane, Atsushi Kanno, Naokatsu Yamamoto

Proceedings Volume PC12420, PC1242002 (2023) https://doi.org/10.1117/12.2646951

KEYWORDS: Radio optics, Phase only filters, Hybrid fiber radio, Wireless communications, Windows, Radio over Fiber, RF communications, Photodetectors, Optical communications, Optical amplifiers

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Proceedings Article | 9 March 2022 Presentation

High speed 2D-photodetector array device and its application for optical signal processing

Toshimasa Umezawa, Yuki Yoshida, Atsushi Kanno, Naokatsu Yamamoto

Proceedings Volume PC12019, PC120190K (2022) https://doi.org/10.1117/12.2607239

KEYWORDS: Optical signal processing, Wireless communications, Telecommunications, Radio optics, Phase retrieval, Free space optics, Optical instrument design, Signal to noise ratio, Signal detection, Reconstruction algorithms

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Proceedings Article | 11 March 2020 Paper

3D printed assembly and software development for silicon photonics sensor device measurement

N. Ittipratheep, S. Udomsom, U. Mankong, P. Chamsuk, A. Bouthwong, W. Anukool, T. Umezawa, A. Matsumoto

Proceedings Volume 11331, 113310E (2020) https://doi.org/10.1117/12.2553021

KEYWORDS: Silicon, Sensors, 3D metrology, Silicon photonics, Resonators, Software development, Measurement devices

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Proceedings Article | 10 March 2020 Presentation

90-GHz +15 dBm high-output integrated photoreceiver driven by only photonic power supply (Conference Presentation)

Toshimasa Umezawa, Atsushi Kanno, Pham Dat, Atsushi Matsumoto, Kouichi Akahane, Naokatsu Yamamoto, Tetsuya Kawanishi

Proceedings Volume 11279, 112791L (2020) https://doi.org/10.1117/12.2543105

KEYWORDS: Power supplies, Optical fibers, Radio over Fiber, Phase only filters, Hybrid fiber radio, Photodetectors, Space division multiplexing, Multiplexing, Receivers, Signal attenuation

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Proceedings Article | 9 March 2020 Presentation

Fabrication of a laser diode at 1600 nm with InAs quantum dots using a digital embedding method on an InP(311)B substrate (Conference Presentation)

Kouichi Akahane, Hiroyuki Yamamoto, Atsushi Matsumoto, Toshimasa Umezawa, Hideyuki Sotobayashi, Naokatsu Yamamoto

Proceedings Volume 11301, 1130108 (2020) https://doi.org/10.1117/12.2544589

KEYWORDS: Semiconductor lasers, Indium arsenide, Quantum dots, Superlattices, Metals, Waveguides, Laser damage threshold, Semiconducting wafers, Molecular beam epitaxy, Cladding

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Proceedings Article | 26 April 2019 Paper

Crosstalk analysis in high speed two-dimensional photodetector array directly coupled to multi-core fibers

Toshimasa Umezawa, Naokatsu Yamamoto

Proceedings Volume 11031, 1103110 (2019) https://doi.org/10.1117/12.2520407

KEYWORDS: Optical fibers, Photodetectors, Personal digital assistants, Optical alignment, Electromagnetism, Metals, Waveguides, Signal detection, Light sources and illumination, Data communications

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Proceedings Article | 4 March 2019 Paper

Optical wireless power grid technology for extreme environments

Naokatsu Yamamoto, Atsushi Matsumoto, Toshimasa Umezawa

Proceedings Volume 10910, 109101X (2019) https://doi.org/10.1117/12.2510799

KEYWORDS: Satellites, High power lasers, Semiconductor lasers, Free space optics, Laser optics, Satellite communications, Geometrical optics, Fiber lasers, Ocean optics, Optical fibers

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Proceedings Article | 1 February 2019 Presentation + Paper

Improvement of cross-talk of high-speed 2D photodetector array

Ken Kusakata, Toshimasa Umezawa, Naokatsu Yamamoto, Tetsuya Kawanishi

Proceedings Volume 10945, 109450O (2019) https://doi.org/10.1117/12.2507743

KEYWORDS: Photodetectors, Optical fibers, Metals, Single mode fibers, Gold, Optical instrument design, Multiplexers, Signal processing, Personal digital assistants, Signal detection

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Proceedings Article | 1 February 2019 Presentation + Paper

Numerical investigation on spatial coherent matched detection for detection of spatially multiplexed signals

Takahide Sakamoto, Toshimasa Umezawa, Naokatsu Yamamoto, Tetsuya Kawanishi

Proceedings Volume 10947, 109470B (2019) https://doi.org/10.1117/12.2509260

KEYWORDS: Signal detection, Multiplexing, Personal digital assistants, Digital signal processing, Phase shifts, Signal processing, Target detection, Heterodyning, Spatial filters, Optical fibers

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Proceedings Article | 5 March 2018 Paper

Silicon photonic resonator for label-free bio-sensing application

Suruk Udomsom, Ukrit Mankong, Nipon Theera-Umpon, Nattapol Ittipratheep, Toshimasa Umezawa, Atsushi Matsumoto, Naokatsu Yamamoto

Proceedings Volume 10714, 107140T (2018) https://doi.org/10.1117/12.2300961

KEYWORDS: Resonators, Refractive index, Silicon, Waveguides, Silicon photonics, Biosensing, Molecules, Sensors, Coating, Nanowires

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Proceedings Article | 23 February 2018 Paper

Study of high power generation in UTC-PD at 110-210 GHz

Toshimasa Umezawa, Atsushi Kanno, Kouichi Akahane, Atsushi Matsumoto, Naokatsu Yamamoto, Tetsuya Kawanishi

Proceedings Volume 10531, 1053115 (2018) https://doi.org/10.1117/12.2287589

KEYWORDS: Capacitance, Photodetectors, Wireless communications, Chromium, Absorption, Photodiodes, Terahertz radiation, Diffusion, Indium gallium arsenide, Waveguides

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Proceedings Article | 20 February 2017 Presentation + Paper

Temperature dependence of gain in a highly stacked quantum-dot semiconductor optical amplifiier

Naoya Yoshida, Yuu Fukae, Kouichi Akahane, Naokatsu Yamamoto, Atsushi Matsumoto, Toshimasa Umezawa, Hideyuki Sotobayashi

Proceedings Volume 10100, 1010017 (2017) https://doi.org/10.1117/12.2251194

KEYWORDS: Semiconductor optical amplifiers, Semiconductors, Optical amplifiers, Indium arsenide, Quantum dots, Fiber optic communications, Optical components, Temperature metrology, Optical communications, Photon transport

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Proceedings Article | 28 January 2017 Presentation + Paper

High-voltage optical power delivery using a light-wave-modulation method

Naokatsu Yamamoto, Toshimasa Umezawa, Atsushi Matsumoto, Kouichi Akahane, Atsushi Kanno, Atsushi Kobayashi, Hiroshi Takai

Proceedings Volume 10128, 101280F (2017) https://doi.org/10.1117/12.2250819

KEYWORDS: Radio optics, Modulation, Optical fibers, Receivers, Phase only filters, Transformers, Photonics, Photodetectors, Antennas, Light sources

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Proceedings Article | 28 January 2017 Presentation + Paper

High-responsivity 100GHz waveguide UTC photodetector

T. Umezawa, K. Akahane, A. Matsumoto, A. Kanno, N. Yamamoto, T. Kawanishi

Proceedings Volume 10128, 1012807 (2017) https://doi.org/10.1117/12.2250246

KEYWORDS: Waveguides, Cladding, Photodetectors, Back illuminated sensors, Indium gallium arsenide, Structured optical fibers, Absorption, Optical fibers, Palladium, Measurement devices

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Proceedings Article | 25 February 2016 Paper

High-efficiency W-band hybrid integrated photoreceiver module using UTC-PD and pHEMT amplifier

T. Umezawa, K. Katshima, A. Kanno, K. Akahane, A. Matsumoto, N. Yamamoto, T. Kawanishi

Proceedings Volume 9747, 97470D (2016) https://doi.org/10.1117/12.2209735

KEYWORDS: Amplifiers, Optical amplifiers, Photodetectors, Connectors, Wireless communications, Transistors, Radio over Fiber, Interfaces, Metals, Waveguides

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Proceedings Article | 16 March 2015 Paper

Monolithically integrated quantum dot optical gain modulator with semiconductor optical amplifier for 10-Gb/s photonic transmission

Naokatsu Yamamoto, Kouichi Akahane, Toshimasa Umezawa, Tetsuya Kawanishi

Proceedings Volume 9359, 93591E (2015) https://doi.org/10.1117/12.2077346

KEYWORDS: Integrated optics, Photonic devices, Quantum dots, Terahertz radiation, Optical modulators, Modulators, Semiconductor optical amplifiers, Data transmission, Gallium arsenide, Quantum optics

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Proceedings Article | 14 March 2015 Paper

High-performance PIN photodetector at 67 GHz and beyond for radio over fiber applications

T. Umezawa, K. Akahane, N. Yamamoto, A. Kanno, T. Kawanishi

Proceedings Volume 9362, 93620T (2015) https://doi.org/10.1117/12.2078616

KEYWORDS: Absorption, Photodetectors, Resistance, Hybrid fiber radio, Palladium, Radio over Fiber, Metals, Indium gallium arsenide, Signal detection, Fourier transforms

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Showing 5 of 20 publications

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