Kouichi Akahane

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We examine the timing dependence of nanophotonic devices based on optical excitation transfer via optical near-field interactions at the nanometer scale. We theoretically analyze the dynamic behavior of a two-input nanophotonic switch composed of three quantum dots based on a density matrix formalism while assuming arrival-time differences, or skew, between(More)
We theoretically and experimentally evaluated energy dissipation of nanophotonic devices based on energy transfer via near-field interactions and their interfaces with optical far-fields. The lower bound is about 10 4 times more energy-efficient than electronic devices. We also examined some fundamental differences between near-field-mediated optical energy(More)
To open up a 1-microm waveband for photonic transport systems, we developed a hybrid and harmonically mode-locked semiconductor laser (MLL) that can transmit return-to-zero (RZ) optical signals at data rates on the order of gigabits per second. A single-mode hole-assisted fiber (HAF) was also developed for use as a 1-microm waveband signal transmission(More)
In this study, we report the effect of the excitation of non-exciton components caused by broadband pulses on quantum beat oscillation. Using a spectrally controlled pump pulse, a long-lived oscillation is clearly observed, and the pump-power dependence shows the suppression of the dephasing rate of the oscillation. Our results from incoherent carrier(More)
We successfully designed and fabricated a high-conversion-gain 100-GHz photoreceiver integrated with a UTC-PD and a PHEMT amplifier for 92-GHz carrier photonic wireless communication. Then, in a demonstration of 92-GHz carrier, OFDM, 16-QAM photonic wireless communication, we confirmed that high data rate of 11.03-Gbps (bit error rate of(More)
Error-free Gbps-order high-speed optical data signal generation in a > 5.5-THz ultra-broad optical frequency bandwidth of the O-band was successfully demonstrated using a newly developed quantum dot electro-optic modulator integrated with a semiconductor optical amplifier.
This paper describes high-speed optical modulation and detection devices for radio-over-fibre (RoF) systems which can distribute millimetre-wave signals over optical fibres with low-loss, and RoF-based high-performance imaging systems which can be used for foreign object debris in runways or railways. High-speed and high-sensitivity photo-detection would be(More)