Norihiro Umeda

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A scanning probe optical microscope using the Wiener fringe is presented. The Wiener fringe is formed by a standing wave between the incident and reflected waves on an optically reflective surface and is detected by inserting an optical fiber tip into the fringe-field region. The detected signal is used to maintain the tip-sample distance constant so that a(More)
This paper reports a method for rapid prototyping of cell tissues, which is based on a system that extrudes, aspirates and refills a mixture of cells and thermoreversible hydrogel as a scaffold. In the extruding mode, a cell-mixed scaffold solution in the sol state is extruded from a cooled micronozzle into a temperature-controlled substrate, which keeps(More)
− Recently, the surface profiles of subwavelength structure have been reduced in size in order to develop microfabrication techniques. In particular, feature sizes of a few tens of nanometres are common in the semiconductor industry. This study uses a Mueller matrix polarimeter, which is based on a scatterometry technique, to evaluate the surface profiles(More)
Tuning characteristics of power, intramode beat frequency, and polarization of 633-nm internal mirror lasers filled with natural Ne or (20)Ne are studied. It is found that the tuning curve of a polarization signal is S-shaped for the natural Ne laser, whereas that of the intramode beat frequency is S-shaped for the (20)Ne laser. The characteristic(More)
Measurements of refractive indices (RIs) of intracellular components can provide useful information on the structure and function of cells. The present study reports, for the first time, determination of the RI of an isolated mitochondrion in isotonic solution using retardation-modulated differential interference contrast microscopy. The value was 1.41 ±(More)
A Au nanofin array embedded in SiO<sub>2</sub> was designed and fabricated to achieve an achromatic half waveplate with high transmittance at visible wavelengths. On the basis of the waveguide theory of nanogaps and the Fresnel reflection theory, nanofin array is calculated to have ideal properties for an achromatic half-waveplate in the visible band from(More)
The light emitted by a stabilized 633-nm He-Ne transverse Zeeman laser (STZL) is composed of two linearly polarized components that are perpendicular to each other. Optical frequencies of the two components are different, and therefore the light changes its polarization with time. The change is represented on the Poincaré sphere as a spin along the equator(More)
The size of a particle smaller than the diffraction limit is measured using a conventional optical microscope by adopting a standing evanescent field illumination. The scattering intensity from a nanoparticle is periodically modulated by shifting the intensity fringes of the standing evanescent field. By measuring contrast of scattering intensity variation(More)
In traditional job scheduling systems for the grid, a single or a few machines handle information of all computing resources and scheduling tasks. This centralized approach is not scalable, since it introduces single point of failure and bottleneck. Some decentralized scheduling systems have been proposed to improve scalability. They avoid concentration of(More)
Metallic zinc nanoparticles (NPs) of 5-15 nm in diameter, formed in silica glass (SiO(2)) by Zn ion implantation of 60 keV, showed a strong ultraviolet absorption peak at around 4.8 eV, which has been assigned as the surface plasmon resonance (SPR) of Zn NPs, and another small peak at 1.2 eV, which has never been reported before. To identify the origin of(More)