Natsuki Hayasaka
Sophia University
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Publication
Featured researches published by Natsuki Hayasaka.
2017 5th International Workshop on Low Temperature Bonding for 3D Integration (LTB-3D) | 2017
Natsuki Hayasaka; Tetsuo Nishiyama; Yuya Onuki; Naoki Kamada; Xu Han; Periyanayagam Gandhi Kallarasan; Kazuki Uchida; Hirokazu Sugiyama; Masaki Aikawa; Kazuhiko Shimomura
Lasing characteristics dependent on the bonding temperature for 1.5μm GalnAsP LD grown on directly bonded InP/Si substrate was successfully obtained. We have grown laser structure by MOVPE using InP/Si substrate, and fabricated broad area edge-emitted LD. For the preparation of InP/Si substrate, the temperature during direct bonding process was changed to 350, 400, and 450 °C. The electrical and lasing characteristics dependent on the bonding temperature were compared.
2017 5th International Workshop on Low Temperature Bonding for 3D Integration (LTB-3D) | 2017
Masaki Aikawa; Tetsuo Nishiyama; Yuya Onuki Naoki Kamada; Xu Han; Gandhi Kallarasan Periyanayagam; Kazuki Uchida; Hirokazu Sugiyama; Natsuki Hayasaka; Kazuhiko Shimomura
Bonding temperature dependence on the surface conditions and optical characteristics of MOVPE grown GalnAsP/InP laser structure using directly bonded InP/Si substrate were studied. We have changed the temperature for bonding InP and Si substrate between 350 and 450 °C. The void density and photoluminescence intensity were examined.
Japanese Journal of Applied Physics | 2018
Masaki Aikawa; Yuya Onuki; Natsuki Hayasaka; Tetsuo Nishiyama; Naoki Kamada; Xu Han; Gandhi Kallarasan Periyanayagam; Kazuki Uchida; Hirokazu Sugiyama; Kazuhiko Shimomura
The bonding-temperature-dependent lasing characteristics of 1.5 a µm GaInAsP laser diode (LD) grown on a directly bonded InP/Si substrate were successfully obtained. We have fabricated the InP/Si substrate using a direct hydrophilic wafer bonding technique at bonding temperatures of 350, 400, and 450 °C, and deposited GaInAsP/InP double heterostructure layers on this InP/Si substrate. The surface conditions, X-ray diffraction (XRD) analysis, photoluminescence (PL) spectra, and electrical characteristics after the growth were compared at these bonding temperatures. No significant differences were confirmed in X-ray diffraction analysis and PL spectra at these bonding temperatures. We realized the room-temperature lasing of the GaInAsP LD on the InP/Si substrate bonded at 350 and 400 °C. The threshold current densities were 4.65 kA/cm2 at 350 °C and 4.38 kA/cm2 at 400 °C. The electrical resistance was found to increase with annealing temperature.
conference on lasers and electro optics | 2017
Kazuki Uchida; Tetsuo Nishiyama; Naoki Kamada; Yuya Onuki; Xu Han; Gandhi Kallarasan Periyanayagam; Hirokazu Sugiyama; Masaki Aikawa; Natsuki Hayasaka; Kazuhiko Shimomura
We have successfully obtained GalnAsP stripe laser grown on InP/Si substrate by MOVPE. InP/Si substrate was prepared by direct wafer bonding technique using epitaxial grown 1μm thickness InP and silicon substrate. 1.2μm wavelength GalnAsP double heterostructure laser was grown by MOVPE, and stripe laser was fabricated using standard SiO2 deposition and lithography. Room temperature lasing was obtained under pulsed condition.
conference on lasers and electro optics | 2017
Hirokazu Sugiyama; Tetsuo Nishiyama; Naoki Kamada; Yuya Onuki; Xu Han; Gandhi Kallarasan Periyanayagam; Masaki Aikawa; Natsuki Hayasaka; Kazuki Uchida; Kazuhiko Shimomura
Low threshold current 1.5pm GalnAsP laser was obtained grown on directly bonded InP/Si substrate using MOVPE. To decrease the threshold current, the thickness and doping condition of p-InP cladding layer were optimized. In the new structure laser, the threshold current became half compared to the previous structure laser, and obtained almost comparable threshold current with the laser grown on InP substrate.
conference on lasers and electro optics | 2018
Periyanayagam Gandhi Kallarasan; Naoki Kamada; Yuya Onuki; Kazuki Uchida; Hirokazu Sugiyama; Xu Han; Natsuki Hayasaka; Masaki Aikawa; Kazuhiko Shimomura
The Japan Society of Applied Physics | 2018
Hiromu Yada; Naoki Kamada; Yuya Onuki; Han Xu; Gandhi Kallarasan Periyanayagam; Masaki Aikawa; Kazuki Uchida; Hirokazu Sugiyama; Natsuki Hayasaka; Shigemasa Sato; Masaki Matsuura; Kazuhiko Shimomura
The Japan Society of Applied Physics | 2018
Gandhi Kallarasan; Naoki Kamada; Yuya Onuki; Kazuki Uchida; Hirokazu Sugiyama; Xu Han; Natsuki Hayasaka; Masaki Aikawa; Kazuhiko Shimomura
The Japan Society of Applied Physics | 2018
Natsuki Hayasaka; Yuya Onuki; Naoki Kamada; Xu Han; Masaki Aikawa; Kazuki Uchida; Hirokazu Sugiyama; Masaki Matsuura; Gandhi Kallarasan Periyanayagam; Hiromi Yada; Kazuhiko Shimomura
The Japan Society of Applied Physics | 2018
Hirokazu Sugiyama; Naoki Kamada; Yuya Onuki; Xu Han; Kazuki Uchida; Gandhi Kallarasan Periyanayagam; Masaki Aikawa; Natsuki Hayasaka; Kazuhiko Shimomura