A Small One-Fiber WDM Optical Ethernet PC Card for FTTD

A new generation of network interface card for fiber-to-the-desktop has been fabricated. The fabricated card is PC-card size and suitable for notebook PCs. It could become the key element in the coming optical Ethernet age.     

Resolving the discrepancy of 135 MeV pd elastic scattering cross sections and relativistic effects

Three precise measurements for elastic pd scattering at 135 MeV/A have been performed with the three different experimental setups. The cross sections are described well by the theoretical predictions based on modern nucleon-nucleon forces combined with three-nucleon forces. Relativistic Faddeev calculations show that relativistic effects are restricted to backward angles. This result supports the two measurements recently reported by RIKEN and contradicts the KVI data.     

Sliding acceleration of water droplets on a surface coated with fluoroalkylsilane and octadecyltrimethoxysilane

Both fluoroalkylsilane (FAS) and octadecyltrimethoxysilane (ODS) were coated on oxidized silicon wafers using soaking and CVD method. Smooth coatings with Ra values of less than 1 nm were attained. The slope of the sliding acceleration against the inverse of the droplet mass showed an inflection point. That point shifted to the direction of smaller droplets with decreasing FAS ratio to ODS. The water droplets’ length was increased when the sliding velocity was increased. Fluoroalkylsilane addition to ODS increases the interaction between water and the hydrophobic surface. Results showed that the sliding acceleration of a water droplet depends strongly on the surface ratio of these silanes.     

Moduli space of non-abelian vortices

We completely determine the moduli space M(N,k) of k vortices in U(N) gauge theory with N Higgs fields in the fundamental representation. Its open subset for separated vortices is found as the symmetric product (CxCP(N-1))k/(see text)k. Orbifold singularities of this space correspond to coincident vortices and are resolved resulting in a smooth moduli manifold. The relation to K?hler quotient construction is discussed.     

Performance Test of CW 300?GHz Gyrotron FU CW I

A 300 GHz CW gyrotron FU CW I has been developed and installed in the Research Center for Development of Far-Infrared Region, University of Fukui as a power source of a high frequency material processing system. Its performance was tested and the maximum power of 1.75 kW / CW has been attained at the beam voltage of 15 kV and the beam current of 1A. The maximum window power efficiency of 15.5% has been obtained at the cathode voltage slightly lower than 15 kV. This gyrotron is designed to deliver a Gaussian beam after mode conversion from the oscillation mode TE_22,8 in the cavity with a complex of an internal radiator and beam shaping mirrors. The detailed measurement with an infrared camera has confirmed that a Gaussian beam is radiated when the magnetic field strength B _c at the cavity is adjusted at a proper value. However, within a range of B _c , the output power is emerged into multiple directions, which suggests simultaneous oscillation of competing cavity modes.     

Radiative carrier recombination dependent on temperature and well width of InGaN/GaN single quantum well

Photoluminescence (PL) spectra and time-resolved PL are measured from around 10 to 300 K for the InGaN/GaN single quantum wells (SQWs) with well widths of 1.5, 2.5, 4 and 5 nm. For the SQWs with the well widths of 1.5 and 2.5 nm, the peak position of PL exhibits an S-shaped shift with increasing temperature. The radiative recombination time τ_RAD begins to increase at the temperature for the position to change from the red-shift to the blue-shift. The steep increase of τ_RAD is observed beyond the temperature from the blue-shift to the red-shift. For the SQWs with the well widths of 4 and 5 nm, the peak position of PL exhibits a monotonic red-shift. τ_RAD decreases at first and then increases with temperature. It is about 100-times longer in the low temperature region and about 10-times longer at room temperature as compared with those of the SQWs with narrower widths.