Prof. Kazutoshi Kato Profile

Prof. Kazutoshi Kato

at Kyushu Univ

SPIE Involvement:

Author

Publications (13)

Proceedings Article | 13 March 2023 Paper

Passive WR3 combiner with a reflector-integrated horn for 50 dB gain

Ming Che, Kazutoshi Kato

Proceedings Volume 12420, 1242004 (2023) https://doi.org/10.1117/12.2647226

KEYWORDS: Terahertz radiation, Reflection, Antennas, Wireless communications, Waveguides, Reflectors, 3D printing, Transmitters, Lenses, Optical simulations

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Proceedings Article | 4 March 2022 Presentation + Paper

Full-C-band high-speed high-reliability wavelength switching at tunable DFB laser array with current/temperature cooperative control

Shenghong Ye, Ming Che, Takeshi Kuboki, Kazutoshi Kato

Proceedings Volume 12021, 1202102 (2022) https://doi.org/10.1117/12.2604422

KEYWORDS: Switching, Tunable lasers, Field programmable gate arrays, Feedback control, Control systems, Optical communications

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Proceedings Article | 20 August 2020 Presentation + Paper

Terahertz-wave beam control by photonics technology

Kazutoshi Kato

Proceedings Volume 11499, 1149902 (2020) https://doi.org/10.1117/12.2567849

KEYWORDS: Terahertz radiation, Phase shifts, Beam steering, Phased array optics, Light sources, Silica, Beam controllers, Photonics, Photonic integrated circuits

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Proceedings Article | 2 March 2020 Presentation + Paper

1THz one-sided directional slot antenna on a chip connected with InAs HEMT

Haruichi Kanaya, Ryo Takigawa, Kohei Tasaki, Kazutoshi Kato, Tanemasa Asano

Proceedings Volume 11279, 1127904 (2020) https://doi.org/10.1117/12.2543439

KEYWORDS: Antennas, Terahertz radiation, Metals, Field effect transistors, Indium arsenide, Sensors, Dielectrics, Image processing, Transistors, Electrodes

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Proceedings Article | 1 March 2019 Presentation + Paper

600GHz wideband planar array antenna on a chip

Haruichi Kanaya, Kota Tsugami, Yang Zhou, Kazutoshi Kato

Proceedings Volume 10917, 109171P (2019) https://doi.org/10.1117/12.2506432

KEYWORDS: Antennas, Terahertz radiation, Optical components, Integrated optics, Wireless communications, Phased arrays, Phased array optics

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The application using the frequency range from 100 GHz to 10 THz has attracted much attention, especially in broadband and higher data-rate wireless communication. In the THz broadband wireless devices, photo mixing by using the uni-traveling carrier photodiode (UTCPD) on the indium phosphide (InP) substrate is a crucial component. UTCPD can down-convert the optical signal to THz wave. To reduce the loss of the connection area between the optical section and the THz section, THz-band antennas and transition lines should be fabricated on the same substrate as the optical section. In our previous research, 1 x 4 and 4 x 4 planar array antennas using one-sided directional slot dipole antenna elements and branched coplanar waveguide (CPW) are connected to the output of UTCPD on the InP substrate for the 300 GHz application. In this presentation, wideband 600 GHz one-sided directional slot antenna was designed. The antenna is based on the slot antenna on the top with the bottom floating metal layer. To enhance the bandwidth, round shape of the edge of the top metal layer was introduced. Moreover, 2 kinds of the antenna element with different resonance frequencies are designed. Antenna 1 (Ant1) has a center frequency = 600 GHz and gain = 2.23dBi. Antenna 2 (Ant2) has a center frequency = 650 GHz and gain = 3.28dBi. The whole size of the antenna elements is 290 um x 230 um and 280 um x 290 um, respectively. Each antenna element is connected to the UTCPD and optical waveguide through a coplanar waveguide (CPW) feed line. Next, we designed a 2-dimensional antenna array with 12 antenna elements. To enhance the bandwidth 4 Ant1s and 8 Ant2s are combined on the InP substrate. From the electromagnetic simulation, this array antenna has antenna gain = 11.89 dBi, 3-dB bandwidth =130 GHz and front-to-back ratio = 15.73 dB. The array size is 1,500 um x 1,500 um. The relative bandwidth can be enhanced from 5 % (reference array antenna) to 20 %. Moreover, by changing the delay line attached to the optical fiber, it is easy to obtain the phase difference of each antenna element. From the results, our proposed phased array antenna has a wideband, high gain and beam tilt characteristics.

Proceedings Article | 23 February 2018 Paper

Development of 4x4 phased array antenna on chip for 300GHz band application

Haruichi Kanaya, Kota Tsugami, Goki Sakano, Guan Chai Eu, Kazutoshi Kato

Proceedings Volume 10531, 1053114 (2018) https://doi.org/10.1117/12.2287326

KEYWORDS: Antennas, Terahertz radiation, Phased arrays, Telecommunications, Beam steering, Photodiodes, Waveguides

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Proceedings Article | 24 February 2017 Paper

4x4 planar array antenna on indium phosphide substrate for 0.3-THz band application

Haruichi Kanaya, Masahiko Koga, Kota Tsugami, Guan Chai Eu, Kazutoshi Kato

Proceedings Volume 10103, 101031N (2017) https://doi.org/10.1117/12.2248859

KEYWORDS: Antennas, Terahertz radiation, Indium, Metals, Wireless communications, Photodiodes, Transceivers, Dielectrics, Waveguides, Photography

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Proceedings Article | 25 February 2016 Paper

Coherent THz wave combiner composed of arrayed uni-traveling carrier photodiodes and planar lightwave circuit

K. Sakuma, J. Haruki, G. Sakano, K. Kato, S. Hisatake, T. Nagatsuma

Proceedings Volume 9747, 97471O (2016) https://doi.org/10.1117/12.2212017

KEYWORDS: Detector arrays, Terahertz sources, Terahertz radiation, Photonic integrated circuits, Photodiodes, Silica, Integrated optics, Antennas, Diodes, Sensors, Control systems, Optical amplifiers, Photography, Active optics, Channel projecting optics

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Proceedings Article | 25 February 2016 Paper

Planar array antenna with director on indium phosphide substrate for 300GHz wireless link

Haruichi Kanaya, Tomoki Oda, Naoto Iizasa, Kazutoshi Kato

Proceedings Volume 9747, 974722 (2016) https://doi.org/10.1117/12.2205421

KEYWORDS: Antennas, Terahertz radiation, Metals, Indium, Wireless communications, Photodiodes, Diodes, Transceivers, Dielectrics, Waveguides, Photography, Telecommunications, Gold

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Proceedings Article | 30 January 2012 Paper

Improvement of coherence length in a 200-kHz swept light source equipped with a KTN deflector

Shogo Yagi, Kazunori Naganuma, Tadayuki Imai, Yasuo Shibata, Jun Miyazu, Masahiro Ueno, Yuuichi Okabe, Yuzo Sasaki, Kazuo Fujiura, Masahiro Sasaura, Kazutoshi Kato, Masato Ohmi, Masamitsu Haruna

Proceedings Volume 8213, 821333 (2012) https://doi.org/10.1117/12.908210

KEYWORDS: Crystals, Light sources, Optical coherence tomography, Optical filters, Electro optics, Coherence (optics), Refractive index, Electrodes, Point spread functions, Data acquisition

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Proceedings Article | 12 February 2011 Paper

A mechanical-free 150-kHz repetition swept light source incorporated a KTN electro-optic deflector

Shogo Yagi, Kazunori Naganuma, Tadayuki Imai, Yasuo Shibata, Shigeo Ishibashi, Yuzo Sasaki, Masahiro Sasaura, Kazuo Fujiura, Kazutoshi Kato

Proceedings Volume 7889, 78891J (2011) https://doi.org/10.1117/12.876024

KEYWORDS: Crystals, Optical coherence tomography, Electro optics, Light sources, Optical filters, Refractive index, Laser crystals, Spectral resolution, Data acquisition, Kerr effect

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Proceedings Article | 5 March 2008 Paper

Single-mode 140 nm swept light source realized by using SSG-DBR lasers

N. Fujiwara, R. Yoshimura, K. Kato, H. Ishii, F. Kano, Y. Kawaguchi, Y. Kondo, K. Ohbayashi, H. Oohashi

Proceedings Volume 6847, 684713 (2008) https://doi.org/10.1117/12.765392

KEYWORDS: Wavelength tuning, Optical coherence tomography, Terahertz radiation, Light sources, S band, Tunable filters, Image enhancement, Semiconductor lasers, Absorption, Oscilloscopes

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Proceedings Article | 2 May 1994 Paper

Ultrawide-bandwidth 1.55-um waveguide p-i-n photodiode

Kazutoshi Kato, Junichi Yoshida

Proceedings Volume 2149, (1994) https://doi.org/10.1117/12.175271

KEYWORDS: Indium gallium arsenide, Waveguides, PIN photodiodes, External quantum efficiency, Internal quantum efficiency, Palladium, Electrodes, Optical properties, Photodetectors, Quantum efficiency

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Showing 5 of 13 publications

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