We report error-free transmission of 64x10 Gb/s channels with 50 GHz spacing using high power, flat gain (35nm bandwidth) erbium-doped silica fiber amplifiers. The amplifier spacing was 80-90 km, and the total end-of-...
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ISBN:
(纸本)8489900140
We report error-free transmission of 64x10 Gb/s channels with 50 GHz spacing using high power, flat gain (35nm bandwidth) erbium-doped silica fiber amplifiers. The amplifier spacing was 80-90 km, and the total end-of-system gain nonuniformity among the 64 channels was 6.4 dB..
Some critical (but little-recognized) aspects of nanoscale electron device technology are considered. According to history, nanoscale electron devices will have to address some convergence of an abundance and a scarci...
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Some critical (but little-recognized) aspects of nanoscale electron device technology are considered. According to history, nanoscale electron devices will have to address some convergence of an abundance and a scarcity. A major impediment to progress is the emergence of a variety of granularities - a problem as much intellectual as material.
Analytical and experimental work has been performed on the use of a magneto-rheological (MR) fluid brake for controlling torsional vibrations in rotating systems. In this paper, two different strategies are examined f...
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ISBN:
(纸本)0819457418
Analytical and experimental work has been performed on the use of a magneto-rheological (MR) fluid brake for controlling torsional vibrations in rotating systems. In this paper, two different strategies are examined for controlling the MR brake in such applications. First, implementation of the MR fluid brake as a passive friction damper with a variable friction torque is presented. In that application, fixed currents were applied to the electromagnets in the MR brake. As a result, the dominant behavior of the brake was as a dry friction damper whose friction was a function of applied current. The second approach was the implementation of the MR brake in a modified skyhook damping control approach. In that application, the friction in the MR brake was adjusted according to a comparison between the sign of absolute velocity of the primary system and the sign of the relative velocity between the MR brake and the primary system in order to add effective damping to the system. Characterization of the MR brake was an essential part of both control strategies. This work includes the results of system identification performed on the MR fluid brake, along with experimental performance results of the system under the different control strategies.
Summary form only given. We describe a novel technique to determine the homogeneous linewidths of surface plasmon resonances of metal nanoparticles in the presence of inhomogeneous broadening and thus measure the deca...
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ISBN:
(纸本)0780363183
Summary form only given. We describe a novel technique to determine the homogeneous linewidths of surface plasmon resonances of metal nanoparticles in the presence of inhomogeneous broadening and thus measure the decay time T/sub 2/. The method is based on spectral hole burning in the inhomogeneously broadened absorption profiles of metal nanoparticles and has been applied to supported oblate Ag clusters with radii of 7.5 nm. From the experimental results and a theoretical model of hole burning the linewidth of 260 meV corresponding to a decay time of 4.8 fs was extracted. This value is shorter than expected for damping by bulk electron scattering. We conclude that additional damping mechanisms, in particular surface scattering, come into play if the electrons are confined in particles with sizes below 10 nm. Furthermore, an influence of the shape of the clusters on the decay time was observed.
A free-space broadband measurement technique is proposed to determine the dielectrics properties of powders and liquids [1]. Two techniques are presented based on horizontal and vertical propagation, both of which all...
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ISBN:
(纸本)9781479924318
A free-space broadband measurement technique is proposed to determine the dielectrics properties of powders and liquids [1]. Two techniques are presented based on horizontal and vertical propagation, both of which allow for a series of measurements to be taken where the varying parameter is thickness of material under test (to overcome the challenge of the unknown electrical length). The horizontal propagation measurements would require an extra containment layer for powders and liquids, which would have consequent mechanical and also computational difficulties. The vertical propagation measurements on the other hand show more promise, both in terms of mechanical containment and also in the inversion of the measured S-parameters to arrive at the complex electric permittivity. The measurements were performed in a large hall and also in an anechoic chamber. To minimise measurement errors a free-space Thru-Reflect-Line/Match (TRL/M) calibration technique was performed. The initial results reported here are for various glass thicknesses, of unknown chemical composition, in the frequency range of 0.8-6 GHz, although the application to powders and liquids will be apparent.
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