Makoto Okano

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Three-dimensional (3D) photonic crystals containing artificial point defects have been fabricated to emit light at optical communications wavelengths. They were constructed by stacking 0.7-micrometer-period gallium arsenide striped layers, resulting in a 3D "woodpile" photonic crystal. Indium-gallium arsenide-phosphide quantum-well layers emitting at a(More)
In superelastic alloys, large deformation can revert to a memorized shape after removing the stress. However, the stress increases with increasing temperature, which limits the practical use over a wide temperature range. Polycrystalline Fe-Mn-Al-Ni shape memory alloys show a small temperature dependence of the superelastic stress because of a small(More)
Zn[2]-Cys[6] binuclear transcription factors Upc2p and Ecm22p regulate the expression of genes involved in ergosterol biosynthesis and exogenous sterol uptake in Saccharomyces cerevisiae. We identified two UPC2/ECM22 homologues in the pathogenic fungus Candida glabrata which we designated CgUPC2A and CgUPC2B. The contribution of these two genes to sterol(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)
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)
We have theoretically investigated the characteristics of three-dimensional (3D) photonic crystal (PC) waveguides formed by the introduction of dielectric line defects. We show that the guided modes in 3D PC waveguides strongly depend on the volume, position and number of dielectric defects introduced. We have succeeded in designing a waveguide structure(More)
High-Tc superconducting bearings are expected as a key technology for flywheel energy storage systems (FWES). However, low bearing stiffness behavior becomes a serious obstacle to realize FWES. We have so far suggested various kinds of bearing construction to improve the bearing stiffness, but the various improvements of superconducting bearings bring(More)
Three-dimensional (3D) photonic crystals can block photons in any direction and are expected to make possible their ultimate control. However, creating 3D crystals without any unintentional defects over large areas at optical wavelengths has been challenging. For example, opal-based crystals inevitably contain unintentional defects, it is difficult 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)