增益与光强的相关系数对光栅外腔半导体激光器稳态特性的影响

本文引入增益与光强的相关系数h,建立了光栅外腔半导体激光器的稳态模型。数值计算结果表明:激光器的其它参数必须与h相匹配,才能使激光输出的稳定区增大,且可在一定波长范围内进行选频,保证很好的单模性。     

氮激光诱导荧光光谱法对动脉粥样硬化斑块的诊断研究

采用波长为337nm的N_2分子激光作光源,利用激光诱导荧光光谱法测量血管组织的自荧光,选择波长为390nm和476nm处的荧光强度比值可以很好地鉴别动脉血管的正常组织和粥样硬化斑块,阈值为1.25。     

Analysis of microstrip resonators of arbitrary shape

A space-domain approach based on a mixed-potential integral equation formulation is developed for efficient computation of complex resonant frequencies of laterally open microstrip-pitch resonators of arbitrary shape. The effects of the substrate-which may consist of any number of planar, possibly uniaxially anisotropic, dielectric layers-are rigorously incorporated in the formulation by means of the vector and scalar potential Green's functions. The current distribution on the conducting patch is approximated in terms of vector basis functions defined over triangular elements. Computed resonant frequencies, quality factors, modal currents, and far-field radiation patterns are presented for several microstrip resonators. For patches of simple, regular shapes, the results are in agreement with published data obtained by specialized techniques, which, unlike the method presented here, are not easily extendible to arbitrary shapes     

Analytical expressions of the guided mode field distribution:analysis and comparison

Methods for determining the parameters of the three different approximate solutions for the fundamental mode field distribution of Ti:LiNbO₃ optical waveguides by using the variational technique are presented. This analysis gives closer approximation not only to the field distribution, but also to the propagation constant. Comparison with the exact results for the exponential index distribution in depth shows that these trial functions are closer to the real solution. It is also shown that these solutions are as accurate as the effective index method for Ti:LiNbO₃ strip waveguides. The analysis provides an approach for comparing and assessing these solutions     

Pulse compression of CW injection seeded gain-switched diode laser

A commercially available gain-switched diode laser was injection seeded by a CW laser diode to provide a controlled frequency chirped output which was compressed by a grating pair and telescope. Pulses were generated with a width of 12 ps and a peak power of 0.19 W at a repetition rate of 3.2 GHz     

SnO2薄膜气敏光学特性的气敏机理模型

本文作者利用表面态建立一个气敏光学机理模型。较好地解释了SnO_2薄膜的气敏效应,气敏透射光谱,气敏透过率与气体浓度的指数关系,以及饱和现象等。     

一种二维神经网络模型及其应用

本文提出一种二维神经网络模型,并将它用来实时求解一类矩阵方程.理论和模拟结果表明,该网络可以在时常数数量级(纳秒)内求出与准确解任意接近的解.     

达林顿硅光电晶体管的光放大特性

通过提高达林顿硅光电晶体管的光电灵敏度,并用１２Ｖ,０．２５Ａ的小灯泡作为输出发光元件,在２６．５μＷ的红光照射下,器件可输出光电流１００ｍＡ以上,输出光功率为２０００μＷ。     

封装技术评述

评述了当前封装技术的特点以及应用,介绍了多芯片组件、突点互连技术、球栅阵列、板上芯片、板上倒装芯片和柔性电路板上芯片技术以及片上引线与引线上芯片技术。     

多媒体教室的电声系统

文中介绍了多媒体教室的建筑特点及声学特性。同时介绍了有关的电声设备及系统的最佳配置方案。