High-power, wide-temperature range operation of 1.3-/spl mu/m gain-coupled DFB lasers with automatically buried InAsP absorptive grating

DFB lasers operating at 1.3 /spl mu/m with gain-coupling structure show single-mode operation over a wide temperature range of -20/spl sim/85/spl deg/C and up to a high power of 130 mW. These lasers have InAsP absorptive grating, which can be formed by a substantially simplified fabrication process, involving annealing a corrugated InP substrate in an atmosphere of mixed arsine and phosphine.     

1.5 nm direct-tunneling gate oxide Si MOSFET's

In this paper, normal operation of a MOSFET with an ultra-thin direct-tunneling gate oxide is reported for the first time. These high current drive n-MOSFET's were fabricated with a 1.5 nm direct-tunneling gate oxide. They operate well at gate lengths of around 0.1 μm, because the gate leakage current falls in proportional to the gate length, while the drain current increases in inverse proportion. A current drive of more than 1.0 mA/μm and a transconductance of more than 1,000 mS/mm were obtained at a gate length of 0.09 μm at room temperature. These are the highest values ever obtained with Si MOSFET's at room temperature. Further, hot-carrier reliability is shown to improve as the thickness of the gate oxide is reduced, even in the 1.5 nm case. This work clarifies that excellent performance-a transconductance of over 1,000 mS/mm at room temperature-can be obtained with Si MOSFET's if a high-capacitance gate insulator is used     

The operation mechanism of a charge modulation device (CMD) imagesensor

The operational mechanism of the charge modulation device (CMD) as an image sensor is presented. A newly developed device simulator, the transistor analysis program for imagers calculating non-steady-state equations (TRINE) is used in this analysis. Comparison of the calculated results with measured data shows that the model predictions are consistent with measured electrical and optical characteristics within a range of 20%. The operational mechanism has been clarified, and the accuracy of the method proves that it is effective in quantitative device design. The discretization scheme of the cylindrical coordinate system used is also shown     

A small pixel CMD image sensor

A charge modulation device (CMD) imager with pixel dimensions of 7.3 μm(H)×7.6 μm(V) was designed, fabricated, and examined. These pixel dimensions are suitable for an HDTV imager with a 1-in image format. The optical aperture ratio is 34%. The effective number of pixels in the imager is 660 horizontal and 492 vertical. The saturation signal current is 17 μA/pixel at an exposure of 1 lx-s with good linearity of photoconversion characteristics. The peak of its spectral response occurs at a wavelength of 575 nm. The blooming suppression ratio of the CMD was measured to be -122 dB. The sensor produces a high-quality image with no degradation in spatial resolution and no image lag. These features show that the CMD imager is eminently suitable for a further high-resolution imager sensor     

Quantum Oscillations of Thermoelectric Effects in a Pseudo-one-dimensional Electron Gas With a Spin–Orbit Interaction

We consider thermoelectric effects in a pseudo-one-dimensional electron gas (P1DEG) with a spin–orbit interaction (SOI). The SOI splits the dispersion relation of the P1DEG into subbands with an energy gap. We find quantum oscillations in transport coefficients, which coincide with the locations of the subband edges, as a function of the electrochemical potential.     

Automated camerawork for capturing desktop presentations

A novel automated camera control method for capturing desktop presentations is introduced. Typical features and the camerawork of shots that appear frequently in TV programs are discussed. To realise those features in this automated video capturing system, the purpose of camerawork is classified from two points of view: target and aspect-of-target. Then, the correspondence between the classification and typical shots and camerawork is considered. A virtual-frame control algorithm based on this idea is proposed, and its implementation in a video production system. Results are shown that verify this method through two kinds of experiments, virtual video capturing using CG animations and real video capturing of real presentations.     

Liquid Marble Patchwork on Super-Repellent Surface

Liquid marble (LM) is a droplet that is wrapped by hydrophobic solid particles, which behave as a non-wetting soft solid. Based on these properties, LM can be applied in fluidics and soft device applications. A wide variety of functional particles have been synthesized to form functional LMs. However, the formation of multifunctional LMs by integrating several types of functional particles is challenging. Here, a general strategy for the flexible patterning of functional particles on droplet surfaces in a patchwork-like design is reported. It is shown that LMs can switch their macroscopic behavior between a stable and active state on super-repellent surfaces in situ by jamming/unjamming the surface particles. Active LMs hydrostatically coalesce to form a self-sorted particle pattern on the droplet surface. With the support of LM handling robotics, on-demand cyclic activation–manipulation–coalescence–stabilization protocols by LMs with different sizes and particle types result in the reliable design of multi-faced LMs. Based on this concept, a single bi-functional LM is designed from two mono-functional LMs as an advanced droplet carrier.     

Purification of metallurgical‐grade silicon up to solar grade

An estimate has been made of the feasibility of a metallurgical purification process, the NEDO (New Energy and Industrial Technology Development Organization) melt‐purification process, for manufacturing solar‐grade silicon from metallurgical‐grade silicon. Equipment has been developed to pilot manufacturing plant scale. The system comprises an electron‐beam furnace for phosphorus removal and a plasma furnace for boron removal. Each furnace has a mold for directional solidification to remove metallic impurities. The concentration of each impurity in the silicon ingot purified through the whole process satisfied the solar‐grade level. The Solar‐grade silicon produced showed p‐type polarity and resistivity within the range 0·5–1·5 Ω cm. Copyright © 2001 John Wiley & Sons, Ltd.     

Polarimetric Characteristics of sea ice in the sea of Okhotsk observed by airborne L-band SAR

The Phased-Array L-Band SAR (PALSAR) aboard the Advanced Land Observing Satellite (ALOS) is capable of globally acquiring fully polarimetric data. In order to confirm the ability of L-band polarimetric synthetic aperture radar (SAR) to investigate sea ice before the ALOS launch, we conducted a field experiment using an airborne Polarimetric and Interferometric SAR (Pi-SAR) in the Sea of Okhotsk in 1999. This paper presents the analyzed results of data acquired in that experiment. The extracted polarimetric parameters of several ice types suggested that polarimetric coherences and phase differences between right-right (RR) and left-left (LL) are good candidates for discriminating ice types. The polarimetric anisotropy as well as the beta angle of the first eigenvector calculated in the polarimetric decomposition procedure are alternative parameters that are sensitive to ice type differences. Due to the low depolarization characteristics of open water, it could be discriminated from sea ice by scattering entropy in all incidence angle ranges. From the relation between ice thickness and the polarimetric parameters, we found that backscattering coefficients and vertical (VV) to horizontal (HH) backscattering ratio are highly correlated with ice thickness. Since the ratio is sensitive to ice surface dielectric constants, a simple simulation using the integral equation method surface model was conducted by using the physical parameters of typical sea ice. A two-dimensional ice thickness map was derived from an empirical relation between the VV-to-HH backscattering ratio and ice thickness.