Masakazu Sugiyama

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We illustrate the important trade-off between far-field scattering effects, which have the potential to provide increased optical path length over broad bands, and parasitic absorption due to the excitation of localized surface plasmon resonances in metal nanoparticle arrays. Via detailed comparison of photocurrent enhancements given by Au, Ag and Al(More)
Monolithically integrated four-channel distributed feedback (DFB) laser array has been fabricated by metal organic vapor phase epitaxy (MOVPE) selective area growth for 1.55 µm coarse-wavelength division multiplexing (CWDM) systems. Wide-stripe MOVPE selective area growth and electron-beam lithography are used to obtain wide CWDM channel spacing of 20 nm.(More)
The direct conversion of solar energy to electricity can be broadly separated into two main categories: photovoltaics and thermal photovoltaics, where the former utilizes gradients in electrical potential and the latter thermal gradients. Conventional thermal photovoltaics has a high theoretical efficiency limit (84%) but in practice cannot be easily(More)
Quantum dots photonic devices based on the III-V compound semiconductor technology offer low power consumption, temperature stability, and high-speed modulation. We fabricated GaAs nanodisks (NDs) of sub-20-nm diameters by a top-down process using a biotemplate and neutral beam etching (NBE). The GaAs NDs were embedded in an AlGaAs barrier regrown by(More)
We demonstrate a simple and efficient optical coupler for vertical coupling between optical fibers and InP-based waveguides using a slant-etched mirror. The angle of the etched mirror can be controlled by using an aluminum jig with a beveled surface inserted under the substrate during RIE (reactive ion etching) of InP/InGaAsP. The off-chip coupler is(More)
SUMMARY An 8ch, 400 GHz monolithically integrated WDM channel selector featuring an array of quantum well semiconductor optical amplifiers (SOA) and arrayed waveguidegrating demultiplexer is presented. Reduction of fabrication complexity was achieved by using a single step selective area MOVPE to realize the different bandgap profiles for the SOA array and(More)
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