一种光输出功率控制电路

分析了光输出功率控制在光通信中的重要性 ,提出了一种有效的光功率控制电路。实验结果表明 ,该电路对调节和稳定光输出功率非常有效。     

An efficient systematic approach to model extraction for passivemicrowave circuits

This paper introduces a new systematic approach to equivalent circuit model extraction for linear microwave passive circuits directly from full-wave frequency domain simulation. The devices being modeled may be either lossless or lossy. Adaptive frequency sampling is used to minimize the computational effort of EM simulation while critically assisting in determining the pole locations of an RF circuit. A simple circuit model for lossy RF circuits along with a determined starting point of optimization of lumped element component values is also presented in detail. The overall result is an efficient and accurate means to produce a complete equivalent lumped element model for RF circuits that is suitable for use in conventional SPICE-like simulation software     

A performance analysis of all-optical clock extraction circuit based on stimulated Brillouin scattering

In this paper, we develop an analytical method to deal with the timing performance in an optical clock extraction circuit based on stimulated Brillouin scattering (SBS). Three kinds of SBS active filters are considered and their frequency-transfer functions are obtained under the assumption that pump depletion caused by SBS is negligible. When pump depletion is taken into account, an SBS active filter acts as a nonlinear filter. To investigate the timing performance at this situation, we introduce the concept of "dynamic frequency-transfer function" to describe its frequency-response property for a fixed-signal light and pump light. Using the obtained "frequency-transfer function," we give analytical expressions for both root-mean-square (rms) phase jitter and rms amplitude jitter of the extracted optical clock, in which we have taken the impacts of SBS gain, pump light linewidth, optical pulse chirp, and pump detuning into account. Finally, a detailed numerical investigation on the timing performance for the three active filters is presented.     

Laser Diode Pumping High-stability 1047 nm TEM00 Mode CW Nd:YLiF4 Laser

A laser diode (LD) pumping high-stability 1047 nm TEM00 mode Nd: YLiF4 (Nd: YLF) continuous wave (CW) laser is reported in this letter. The laser output power of 5.83 W with optical to optical effidency of 27％ and slope efficiency of 30％ has been achieved The instability of output power is 0.36％ and spike caused by relaxation oscillation has not been observed in the laser beam. The transverse cross section of laser beam is an ellipse, the diameters of laser beam at output mirror in both directions are 0.97 mm and 1.07 mm, respectively. The divergent angles are 0. 936 mrad and 0. 774 mrad, and the values of M2 are 1.37 and 1.24, respectively. The polarization degree of laser beam is better than 237:1.     

Context-based lossless interband compression-extending CALIC

This paper proposes an interband version of CALIC (context-based, adaptive, lossless image codec) which represents one of the best performing, practical and general purpose lossless image coding techniques known today. Interband coding techniques are needed for effective compression of multispectral images like color images and remotely sensed images. It is demonstrated that CALIC's techniques of context modeling of DPCM errors lend themselves easily to modeling of higher-order interband correlations that cannot be exploited by simple interband linear predictors alone. The proposed interband CALIC exploits both interband and intraband statistical redundancies, and obtains significant compression gains over its intrahand counterpart. On some types of multispectral images, interband CALIC can lead to a reduction in bit rate of more than 20% as compared to intraband CALIC. Interband CALIC only incurs a modest increase in computational cost as compared to intraband CALIC.     

Conditions of asymptotic stability for cellular neural networks with time delay

In this paper, global asymptotic stability for cellular neural networks with time delay is discussed using a novel Liapunov function. Some novel sufficient conditions for global asymptotic stability are obtained. Those results are simple and practical than those given by P. P. Civalleri, et al., and have a leading importance to design cellular neural networks with time delay.     

基于UWB的Ad hoc无线网络

介绍了采用超宽带(UWB)技术的Ad hoc无线网络,重点阐述了网络的两个关键技术MAC协议和路由算法协议.     

基于GSM模块TC35i的机房温度测控系统

为满足机房温度控制的实际需求,提出了一种基于GSM（全球移动通信系统）模块TC35i的网络服务器机房温度测控系统,并对整个系统的功能和构成情况进行了阐述。该网络服务器机房温度测控系统采用TI公司MSP430F135超低功耗单片机作为微处理器,结合TC35i模块的特点,实现对温度测控系统的短信报警、短信随时查询、机房参数短信设置等功能。系统可用以代替人工的方法实现机房的24h监控。     

Mg掺杂AlGaN的特性研究

采用金属有机物化学气相淀积方法在Al2O3衬底上生长不同浓度Mg掺杂的AlxGa1-xN合金薄膜,并在750℃、N2气氛下对Mg进行热退火激活。用X射线衍射ω-2θ扫描计算确定样品的Al组分,发现Mg摩尔掺杂浓度和退火对Al组分均未产生明显影响。X射线衍射摇摆曲线与原子力显微镜扫描表明随Mg摩尔掺杂浓度增加,样品晶体质量下降,样品表面凹坑增加,但热退火对薄膜表面形貌有明显的改善。阴极射线发光测量发现带边峰强度随掺杂浓度增加而减弱,退火后样品的施主-受主对复合发射与导带受主的复合发射均有增强,验证了热退火对钝化受主杂质的激活作用,对实现高效AlGaN的p型掺杂具有重要意义。     

新型单芯互连光缆及其连接器

介绍了一种新型单芯互连光缆的结构特点,及其在实际应用中配套使用的各种连接器的结构.说明了单芯互连光缆的主要功能是同时传输光信号和电力,并详细阐述了该光缆在应用中通过其配套的连接器,同时实现光、电连接的过程.