Tomohiro Yamanaka

Learn More
A contactless power transfer system for charging electric vehicles requires a high efficiency, a large air gap, and a good tolerance to lateral misalignment and needs to be compact and lightweight. A double-sided winding 10 kW transformer based on a 1.5 kW H-shaped core transformer was developed for a rapid charger. Even though the transformer capacity was(More)
Incident-power-dependent extinction ratio of electroabsorption modulators is shown and theoretically investigated by using microscopic theory combined with heat-flux calculation. The phenomenon stems from voltage-dependent temperature rise and the calculated results agree well with the experiment.
Band-edge optical properties of highly strained In(Ga)As/InGaAs quantum wells are analyzed by using 6- and 8-band kmiddotp theory. It is shown that the 8-band model is necessary for the analysis of In(Ga)As/InGaAs quantum wells having strain larger than 2%. The photoluminescence peak wavelength and absorption spectra of InAs/InGaAs quantum wells with the(More)
  • 1