Silicon-on-insulator based optical waveguide and integrated switch matrix

zhangdi于2010-03-29批量导入

Performance of an embedded optical vector matrix multiplication processor architecture

An embedded architecture of optical vector matrix multiplier (OVMM) is presented. The embedded architecture is aimed at optimising the data flow of vector matrix multiplier (VMM) to promote its performance. Data dependence is discussed when the OVMM is connected to a cluster system. A simulator is built to analyse the performance according to the architecture. According to the simulation, Amdahl's law is used to analyse the hybrid opto-electronic system. It is found that the electronic part and its interaction with optical part form the bottleneck of system.

Deterministic Column-Based Matrix Decomposition

In this paper, we propose a deterministic column-based matrix decomposition method. Conventional column-based matrix decomposition (CX) computes the columns by randomly sampling columns of the data matrix. Instead, the newly proposed method (termed as CX_D) selects columns in a deterministic manner, which well approximates singular value decomposition. The experimental results well demonstrate the power and the advantages of the proposed method upon three real-world data sets.

Fast calculation technique for scattering in T-matrix method

In scattering calculations using the T-matrix method, the calculation of the T-matrix involves multiplication and inversion of matrices. These two types of matrix operations are time-consuming, especially for the matrices with large size. Petrov et al. [D. Petrov, Y. Shkuratov, G. Videen, Opt. Lett. 32 (2007) 1168] proposed an optimized matrix inversion technique, which suggests the inversion of two matrices, each of which contains half the number of rows. This technique reduces time-consumption significantly. On the basis of this approach, we propose another fast calculation technique for scattering in the T-matrix method, which obtains the scattered fields through carrying out only the operations between matrices and the incident field coefficient. Numerical results show that this technique can decrease time-consumption by more than half that of the optimized matrix inversion technique by Petrov et al. (c) 2008 Elsevier B.V. All rights reserved.

Sol-gel matrix modified microstructured optical fibre towards a fluoride sensitive optical probe

In this article, we report an optical fluoride probe based on microstructured polymer optical fibers (MPOFs) which is modified with morin-Al complex doped silica gel film. This probe is fabricated by sol-gel fluxion coating process. Sol solution doped with morin-Al is directly inhaled into array holes of MPOF and then forms morin-Al-gel matrix film in them. The sensing probe shows different fluorescence intensity to different fluoride ion concentrations in the aqueous solution. The range of response is 550 mmol/L, under the condition of pH 4.6. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.

遥爪丁腈共聚物的增韧环氧－聚氨酯IPN及PVC共混物的合成与表征

Ⅰ. 增韧环氧／聚氨酯互穿网络聚合物的合成与表征 用部分环氧树脂与丁腈羧反应，进行端基转化，制得端环氧基丁腈－环氧共聚物与环氧树脂的混合物，经叔胺固化后，得到增韧环氧（TEpx）。制备了两种IPN体系，体系1为增韧环氧／蓖麻油聚氨酯IPN，体系2为增韧环氧／聚醚聚氨酯IPN。用红外光谱研究了动力学，研究结果是，对于体系1，－OH基与－NCO基的反应速度大于环氧基的聚合速度，因此，IPN体系中，PU网络的形成比环氧网络快。环氧上的－OH基与蓖麻油上的羟基相似。同属伸羟基，它也会与－NCO基反应，因此，所形成的IPN的两网络间，存在着一定程度的化学交联。在增韧环氧的分子结构中，含有丁腈羧低聚物链段，使得增韧环氧与蓖麻油聚氨酯的相容性较好，该因素对这种IPN形态结构的形成，是很重要的，从动态力学性能的测试结果，能说明这个问题，即玻璃化转变峰很宽，在一定组成时，半峰宽几乎达100 ℃。对于体系2，聚氨酯相起反应的羟基是伯羟基，它与－NCO基的反应速度比环氧中的羟基与－NCO基的反应速度大得多。此外，体系中的两组分，即增韧环氧与聚醚聚氨酯的相容性不好，反应速度的差别与相容性的差别，均将导致反应体系中相分离程度的增大。这在tanZ-T曲线上表现得很明显，出现了两个相距甚远的玻璃化转变峰。利用透射电子显微镜对两个IPN体系进行了形态观察，这些IPN具有特殊的结构，既有增韧环氧所存在的两相结构，又有IPN的两相结构。Ⅱ. 聚氯乙烯－丁腈羟低聚物共混物的合成与表征 制备了高聚物（PVC）－低聚物（HTBN）共混物，研究了该共混物的力学性能，阻尼性能及形态结构。研究结果表明，在HTBN中，丙烯腈含量较高时，随着HTBN加入量的增加，PVC的阻尼峰均有不同程度的加宽加高。在力学性能方面，共混物的抗张强度、伸长率也随低聚物中丙烯腈含量的高低而变化，丙烯腈含量较高时（25％，36％），随HTBN加入量的增加，性能变化不大，而丙烯腈含量较低时（15％，5％），当HTBN的加入达一定量时，性能发生突降。这些现象的出现，主要与相容性有关，HTBN中丙烯腈含量高，极性大，与PVC混溶性好，因而阻尼性能、力学性能均好。而HTBN中丙烯腈含量低，与PVC之间的粘合力不好，即混溶性不好，因而共混物性能不好。由TEM照片看，该共混体系的形态结构为细胞状结构，细胞内存在着界面模糊的两相结构，在低丙烯腈含量（15％）时，存在着部分界面清晰的两相结构，形态观察的结果与性能测定的结果一致。

THE MATRIX ANALYSIS FOR AN OPTICAL FREE-SPACE SWITCHING NETWORK AND AN OPTICAL CROSSOVER NETWORK WITH 4-FUNCTION INTERCHANGE NODES

A matrix analysis for free-space switching networks, such as perfect shuffle-exchange omega, crossover and Banyan is presented. On the basis of matrix analysis, the equivalence of these three switching networks and the route selection between input and output ports are simply explained. Furthermore, an optical crossover switching network, where MQW SEED arrays are used as electrically addressed four-function interchange nodes, is described and the optical crossover interconnection of 64 x 64, and high-speed four-function, interchange nodes is demonstrated in the experiment.

MATRIX DESCRIPTION OF DYNAMIC HOLZ DIFFRACTION TESTED ON THE STRAINED LAYER SUPERLATTICE SI/GESI

A matrix formulation has been developed and applied to simulate large-angle convergent-beam electron diffraction (LACBED) patterns from the Si/GexSi1-x strained layer superlattice (SLS). Good quantitative agreement has been achieved between experimental and simulated patterns. By utilizing dynamical HOLZ line patterns, we demonstrate that an accuracy of better than 0.1% can be achieved in the determination of the averaged lattice constant of a SLS, and the averaged number of layers of atoms within one period of SLS can be determined up to a single monolayer.

The scattering matrix method for quantum waveguides

A scattering matrix method for investigating the electron transport in quantum waveguides is presented. By dividing the structure into a number of transverse slices, the global scattering matrix is obtained by the composition of the individual scattering matrices associated with each interface. Complicated geometries and inhomogeneous external potentials are included in the formulation. It is shown that the proposed scattering matrix method possesses many advantages over the traditional mode-matching and transfer matrix methods, especially in treating the electron wave propagation in complicated geometries. Justification for the method is provided by the unitarity of the calculated scattering matrix, and the consistency of the results with those obtained by the recursive Green's function method.

A transfer matrix approach to conductance in quantum waveguides

A transfer matrix approach is presented for the study of electron conduction in an arbitrarily shaped cavity structure embedded in a quantum wire. Using the boundary conditions for wave functions, the transfer matrix at an interface with a discontinuous potential boundary is obtained for the first time. The total transfer matrix is calculated by multiplication of the transfer matrix for each segment of the structure as well as numerical integration of coupled second-order differential equations. The proposed method is applied to the evaluation of the conductance and the electron probability density in several typical cavity structures. The effect of the geometrical features on the electron transmission is discussed in detail. In the numerical calculations, the method is found to be more efficient than most of the other methods in the literature and the results are found to be in excellent agreement with those obtained by the recursive Green's function method.

Photoluminescence studies of single submonolayer InAs structures grown on GaAs (001) matrix

We report a detailed analysis of optical properties of single submonolayer InAs structures grown on GaAs (001) matrix. It is shown that the formation of InAs dots with 1 monolayer (ML) height leads to localization of exciton under certain submonolayer InAs coverage, which play a key role in the highly improved luminescence efficiency of the submonolayer InAs/GaAs structures.

PHOTOLUMINESCENCE STUDIES OF SINGLE SUBMONOLAYER INAS STRUCTURES GROWN ON GAAS (001) MATRIX

Optical properties of single submonolayer InAs structures grown on GaAs (001) matrix are systematically investigated by means of photoluminescence acid time-resolved photoluminescence, It is shown that the formation of InAs dots with 1 ML height leads to localization of excitons under certain submonolayer InAs coverages, which play a key role in the highly improved luminescence efficiency of the submonolayer InAs/GaAs structures. (C) 1995 American Institute of Physics.

An Improved Driving Circuit for Thermo-Optical Switch to Improve the Reliability of Thermo-Optical Switch Matrix

The influence of the heaters on the reliability of the thermo-optic (TO) switch matrix is analyzed and an improved driving circuit based on the analyzed results is designed and fabricated. The circuit can improve the reliability of the switch matrix device from 78.87% to 97.04% for a 4×4 optical switch device with a simplified tree structure. The simulation and experimental results show the circuit can provide suitable driving current for TO switch matrix.