Nobuaki Hatori

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Conversion efficiency to longer wavelengths in four-wave-mixing-based wavelength conversion in optical semiconductor amplifiers is generally much lower than that in the opposite direction. This study demonstrates experimentally that this feature is drastically improved, and the asymmetry between conversion directions is eliminated by using quantum dots in(More)
We theoretically demonstrate that semiconductor optical amplifiers with self-assembled quantum dots can process high bit-rate optical signals over 40 Gbit/s under gain saturation, and have diverse functions like regeneration, reshaping, multiple-wavelength processing, wavelength conversion, and demultiplexing, which meet with the demand of the(More)
This study investigated fluctuations of cytosolic pH (pHi) of cultured rat vascular smooth muscle cells (VSMCs) in reaction to metabolic alterations induced by angiotensin II (AII). Serially passed VSMCs from Wistar rat aortae were grown on coverslips and loaded with the pH-sensitive fluorescent indicator 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein. A(More)
A hybrid integrated light source was developed with a novel configuration in which a laser diode (LD) array was mounted on a silicon optical waveguide platform for inter-chip optical interconnection. An output power uniformity of 1.3 dB was observed at the 13-channel integrated light source with 30-µm pitch. Use of a SiON waveguide with a spot size(More)
Slow-light Mach-Zehnder modulator on SOI substrate is developed, which utilizes cascaded ring resonators in all-pass filter configuration. A fabricated device shows seven-fold enhancement in modulation efficiency, compared with a conventional modulator.
We have developed a spot size converter (SSC) with a trident silicon (Si) waveguide for the hybrid integrated light source in a photonics-electronics convergence system. Low loss coupling was achieved with just the simple planar form of a Si waveguide with no use of complicated structures such as vertical tapers or extra dielectric core overlaid on the(More)
MicroRNA (miRNA) can function as tumor suppressors or oncogenes, and also as potential specific cancer biomarkers; however, there are few published studies on miRNA in synovial sarcomas, and their function remains unclear. We transfected the OncomiR miRNA Precursor Virus Library into synovial sarcoma Fuji cells followed by a colony formation assay to(More)
Engineers are currently facing some technical issues in support of the exponential performance growths in information industries. One of the most serious issues is a bottleneck of inter-chip interconnects. We propose a new "Photonics-Electronics Convergence System" concept. High density optical interconnects integrated with a 13-channel arrayed laser diode,(More)
Silicon optical interposers for inter-chip interconnects, integrated with an arrayed laser diode, an optical splitter, silicon optical modulators and germanium photodetectors on a single silicon substrate were demonstrated. A 12.5-Gbps error-free data transmission and 6.6-Tbps/cm<sup>2</sup> transmission density were achieved.