An all-optical multiplexing technique using wavelength division multiplexing (WDM)-time division multiplexing (TDM) conversion with an electroabsorption wavelength converter has been proposed and demonstrated. The effectiveness of this WDM-TDM conversion technique for various pulsewidth settings was experimentally investigated. The fluctuation of the signal performance, which was inevitably caused by the coherent crosstalk between adjacent pulses in the conventional optical time division multiplexing (OTDM) technique, were successfully suppressed, even in the case of wide pulse duration. High Q-factor performance has been maintained for a wide range of duty ration from 36% to 74%. By introducing this technique to the optical time division multiplexer, a highly stable and high-quality 40-Gb/s optical signal can be effectively produced without generating the short pulse or setting two tributaries at orthogonal polarization states, and without introducing high-speed electronics for signal multiplexing. The WDM-TDM conversion with an electroabsorption wavelength converter was extended to 60-Gb/s operation by using three 20-Gb/s tributaries. A clear eye opening was confirmed for a waveform after the WDM-TDM conversion of the 60-Gb/s signal 相似文献
We present simulation results of the vortex dynamics in a trapped Bose-Einstein condensate in the presence of a rotating optical
lattice. Changing the potential amplitude and the relative rotation frequency between the condensate and the optical lattice,
we find a rich variety of dynamical phases of vortices. In particular, when the optical lattice rotates faster than the condensate,
the competition between the pinning force and the interactions by nucleated interstitial vortices leads to the melting of
vortex lattice, yielding a vortex liquid phase. 相似文献
A strontium tantalum sulfide, SrTa2S5, has a hexagonal structure with lattice constants of a =3.32 and c=24.1 Å. With decreasing temperature the electrical resistivity decreases monotonically and exhibits an abrupt superconducting transition at 3.16 K (midpoint). The diamagnetic susceptibility is observed below Tc. The magnetic susceptibility is nearly independent of temperature above Tc and shows Pauli paramagnetism. 相似文献
When we select No students from N applicants on the basis of a composite score of subtests, it is important to evaluate the contribution of each subtest. The swap-rate, which is defined as the proportion of the applicants who actually pass the examination but would fail if the j-th subtest were not included in the component to rank the applicants, is one of the measures of the contribution of the j-th subtest.
In this article, first, we derive the characteristics and limiting properties of the population swap-rate. Next, using the properties of the order statistics and the extended hypergeometric distribution, we derive an approximation to the asymptotic variance of the sample swap-rate when the number of applicants is large. Finally, we propose the use of our analytic approximation to the variance of the sample swap-rate in the real data problem and show that it is very efficient.
A development of 170GHz/500kW level gyrotron was carried out as R&D work of ITER. The oscillation mode is TE31,8. In a short pulse experiment, the maximum power of 750kW was achieved at 85kV/40A. The efficiency was 22%. In the depressed collector operation, 500kW/36%/50ms was obtained. The maximum efficiency of 40% was obtained at PRF=470kW whereas the power decrease by the electron trapping was observed. Pulse extension was done up to 10s at PRF=170kW with the depressed collector operation. The power was limited by the temperature increase of the output window. 相似文献
In situ surface modification of boehmite (AlOOH) nanoparticles during hydrothermal synthesis in supercritical water was examined by adding CH3(CH2)4CHO and CH3(CH2)5NH2 as modifier reagents to the reactants. Changes in surface properties of the nanoparticles by surface modification was observed by FTIR, dispersion in solvents and TEM analyses, which demonstrated that reagents chemically binded onto the surface of the AlOOH nanoparticles. The results of SEM and TEM pictures show that the surface modification affects crystal growth and reduces the particle size and changes the morphology of the particles. 相似文献
In this paper, we describe two kinds of characteristic nonlinear dynamics in two-component Bose–Einstein condensates. For two overlapping components, we analyzed the collective modes and a variety of nonlinear mode couplings, which were then confirmed by numerical simulation of the time-dependent Gross–Pitaevskii equations. Next, we consider the nonlinear dynamics of two condensates after abruptly turning on the intercomponent coupling strength. For strong intercomponent interactions the out-of-phase density wave of the condensates became unstable, leading to mugtiple domain formation. 相似文献
Two special cases of the bilateral 2-D polynomial matrix equationDU +VN=C whenC=I andC=I with being a -stable 2-D polynomial, which are related respectively to deadbeat and asymptotic control problems of 2-D systems, are first considered. By generalizing the concepts of factor coprimeness, zero coprimeness and zero skew primeness in the 2-D polynomial ring to the ring of causal -stable 2-D rational functions, a constructive solution of these two problems mentioned is proposed. Based on these results, we derive a solvability condition for the bilateral equiation whereC is a general 2-D polynomial matrix. The general solutions are investigated as well. 相似文献