高清视频网络仍是家庭寻觅的目标

我曾为需要能够在整个家庭输送高清电视流的低成本联网技术这个问题所困扰.我仍然相信视频联网应用将为从集成电路供应商到服务提供商以及信息拥有者带来巨大收益.     

Growth of chromium carbide in a hot wall DLICVD reactor

Chromium carbide coatings were grown at 748 K in a hot wall CVD reactor fed by sublimation of bis(benzene)chromium, BBC (MOCVD) and by direct liquid injection using a BBC/toluene solution (DLICVD). The two types of coatings exhibit an amorphous structure and the same C content (22 at.%). DLICVD permits delivering higher mass flow rate of precursors and consequently the growth rate is 3 times higher and the thickness uniformity is better than using MOCVD. Chromium metal deposition has also been investigated by DLICVD in this hot wall reactor using BBC/toluene/additive as precursor. The purpose of the additive is to block carbide formation. Two additives have been studied: (i) hexachlorobenzene (C6Cl6) and (ii) thiophenol (C6H5SH). The ratio additive/BBC required for Cr metal deposition is a few percent. In this process, C6Cl6 is not decomposed and only traces of Cl (0.4 at.%) are found in the coatings. For a ratio C6Cl6/BBC > 27% the growth of any coating is blocked. The gas phase containing C6H5SH is more reactive since the onset of deposition occurs approximately 50 K before the temperature of the chlorinated compound. Furthermore, a sulfur contamination of 3 at.% has been analyzed in the coatings revealing a partial decomposition of the additive. The results are detailed and discussed in relation with previous works.     

PCB原型能在设计过程中增值

您如何使用原型?是否仅做系统设计中那些棘手部件的原型?您反复制造原型PCB,使之与设计保持一致吗?EDN应如何报道PCB设计?     

Optical Distribution and Upconversion of MB-OFDM in Ultrawide-Band-Over-Fiber Systems

Broadband radio-over-fiber networks are raising great interest for intrabuilding distribution and signal processing of ultrawide-band (UWB) signals. In this paper, a unique optical system based on an external modulator biased either in linear or nonlinear regime has been used to realize both distribution of multiband orthogonal frequency-division multiplexing (MB-OFDM) UWB signal and all-optical frequency upconversion of UWB-OFDM subband. The impact of the nonlinearity of the optical link on the MB-OFDM signal is investigated through a simulation model of the complete UWB-over-fiber system. Results have shown enhanced performance of upconverted MB-OFDM subband compared to direct transmission due to optical noise reduction. First experimental results have confirmed simulation results.     

哪种接口更具魅力？

在SAN领域居首要地位的是光纤通道，InfiniBand正在计算机集群领域发展，而具有更快速特点的以太网像一位潜在的万能博士正在隐隐出现。     

New optical microwave up-conversion solution in radio-over-fiber networks for 60-GHz wireless applications

A new method for generating optical microwave mixing based on the optical phase modulation and the fiber chromatic dispersion is further investigated. A theoretical approach based on the analysis of the optical field spectrum has lead to the evaluation of the mixing power and optimal fiber lengths of 60-GHz radio-over-fiber (RoF) networks. Results have shown adaptable fiber lengths to match the network specifications.     

《全球报道3》：全球模拟、电源、系统和IC设计

2004年,我们考虑将全球报道作为每年的一项工作,它将使我们能充分利用我们在全球的编辑资源,并以我们的文章为全球读者服务。读者似乎很欣赏创刊版和2005版,因此我们现在提供第三期年度报道。全世界的工程师都面临着按照国际标准和规定来做设计,其工作的全球市场潜力等全球性问题。我们相信:您将会发现《全球报道3》在这两方面都会给予您启发。今年,我们的全球报道侧重于各种围绕四个设计领域的全球性问题。模拟设计,电源系统设计,基于微处理器的设计、芯片设计。本期全球报道都包含一篇针对上述每个领域的基础文章。此外,每个部分都包含若干篇附文,用其它学科、产品和应用的相关信息来实现全面覆盖,例如测试、可编程逻辑和无线通信。     

Dual concentric core dispersion compensating fibre optimised for WDM application

A dual concentric core fibre exhibiting a chromatic dispersion coefficient around -350 ps/(nm km) is used in a dispersion compensating module designed for WDM application. The optimised length ratio is larger than 20 and the residual chromatic dispersion is measured at 0.4 ps/(nm km) in the C-band     

Efficient Photomodulation of Visible Eu(III) and Invisible Yb(III) Luminescences using DTE Photochromic Ligands for Optical Encryption

This work describes a class of complex combining three dithienylethene units and a lanthanide ion used as an optical system displaying a double encryption method: i) a colorful code, drawn and erased under UV and visible irradiations respectively, due to coloration and discoloration of the photochromic entities, and ii) a concomitant gradual disappearance and progressive restoration of the associated lanthanide ion luminescence triggered with the same stimuli. The innovation of the system stems from the emission color tunability, i.e., with either a lanthanide ion emitting only in the visible range (Eu³⁺) or with another lanthanide ion emitting only in the near infrared (NIR) range (Yb³⁺), therefore observable, or not, to the naked eye. This system is the very first one to achieve efficient repeatable modulation of pure NIR luminescence on photochemical command. Furthermore, it is proven to be highly efficient when embedded in a PDMS polymer opening real opportunities for practical applications as anti‐counterfeiting.     

Optically Tunable Nonlinearities in Polymers Based on Photoisomerizable Metal‐Based Coordination Complexes

The bottom‐up design of polymer films exhibiting quadratic nonlinear optical properties that can be tuned optically and chemically is described. The polymer matrices are doped with metal‐containing chromophores built around a Zn^II core and photoisomerizable ligands with two different geometries. These molecules possess specifically designed photophysical and nonlinear optical properties to be used towards all‐optical poling, an interference process between one‐ and two‐photon excitations that locally induces macroscopic second‐order effects in polymer films. It is shown that grafting the molecules onto the polymer chains improves the stability of the macroscopic photoinduced nonlinearity in the films.