光纤器件流变制造加热方法研究

在光纤器件流变制造加热方法研究中,采用电加热方式取代传统火焰加热方式.设计一种新型熔融拉锥电加热器,并在此基础上研制了一种新型电加热式熔融拉锥机,温度控制精度和稳定性达±2℃,比气体燃烧的方式提高一个数量级.最后,在此新型电加热式熔融拉锥机上制作的光耦合器,并对其性能离散性进行分析对比.结果表明,与火焰加热式熔融拉锥机相比,电加热式熔融拉锥机成倍地提高了器件性能的一致性.     

光波分复用及其在有线电视传输中的应用

本文首先介绍光波分复用的概念、光波分复用器件的类型和主要特性参数，在介绍熔融型光波分复用器的复用原理后，讨论光波分复用在有线电视中的应用方法及其特性参数对有线电视传输系统指标的影响。最后，介绍上海有线电视台利用熔融型光波分复用器有效解决过黄浦江光纤紧缺问题的例子。该例利用两根光纤实现了两路数字信号和两路模拟有线电视信号的传输，为利用光波分复用充分挖掘现有光纤网的潜力提供了成功的例子。     

光迅科技光开关实现批量生产

随着通信业的发展在光器件领域，由于一些低端产品的门槛降低，如连接头，跳线和耦合器等生产厂家相对较多，产品已经出现了过剩，而一些新的、高端的光器件产品的需求量却越来越大。为了顺应市场的需求光迅科技于2001年立项开发光开关经过一年的研究和开发，光迅科技已研制出     

光接入网用光无源器件

为了平稳地过渡到“光纤到家”（ＦＴＴＨ），已经引入了好几种光接入网。除了技术上的考虑外，经济上的可行性在这些网络中也是非常重要的。我们正在研制一些组成这些网络基本部分的廉价、小型、高密度的无源光器件。在本文中，我们叙述了开发这些器件中所采用的先进应用技术。诸如分光器、光分路模块、滤光器、机械式光开关，以及它们的光学和机械性能在文中也作了叙述。     

谐振腔增强型光探测器的高速响应性能研究

高速长波长光探测器是高速光纤通信系统和网络的关键器件，它要求光探测器具有宽的频率响应带宽和高量子效率。常用的PIN光探测器由于量子效率和高速性能均受到吸收层厚度的牵制，使得二者相互制约，成为一对矛盾。谐振腔增强型(RCE)光探测器为这一矛盾的解决提供了有效的方案。基于谐振腔增强型光探测器的实际设计和制作模型，分析了器件吸收层中的光场分布，并将其运用于载流子的连续方程，从理论上详细地分析了器件的高速响应特性，给出了计算结果。针对研制的高速长波长谐振腔增强型光探测器，进行了理论分析和实际器件测试的结果比较，得到了比较一致的结果。     

光传送网中的关键光器件

光器件是光传送网的基础单元之一，本主要综述光传送网中的关键光器件：光源与光探测器、光波分复用/解复用器、光放大器、色度色散与偏振模补偿器及光开关等。比较了各种光器件的主要技术方案，特别针对的是已实用化的技术方案。最后讨论了光器件的尺寸小型化、微型化以及多功能集成等发展趋势，介绍了光器件的集成方式如：传统分立光器件的集成，平面光波导集成，以及混合集成等。     

半导体光开关工作电流和速率的理论分析

本文从载流子连续性方程出发，采用半导体双异质结概念，从理论上推出了计算半导体光波导开关工作电流和速率的理论公式，为器件选取工作电流和提高开关速率提供了理论依据。     

有机聚合物热光器件的热学模型

有机聚合物热光型光波导器件是具有重要应用意义的集成光学器件。本文针对器件中温度场特性在器件性能优化方面的重要性,根据热传导理论,建立了热学模型,文中首先给出了热传导学的基本理论,基于此给出了器件热学模型的分析与建立。此项工作将为器件的计算机辅助设计打下基础。     

光无源器件产业的发展和扩建的建议

简述了光无源器件的发展趋势，分析了市场的需求情况，认为天津市在发展光无源器件的产业方面具有一定的优势和基础，据此提出了发展和扩建天津无源光器件产业的建议。     

光纤光隔离器研制的进展

本文介绍了光隔离器国内外研制的现状与发展，扼要说明光隔离器的原理，结构，分类与器件小型化等问题。最后提出了该器件今后发展方面的几个问题。     

Comparison of experimental and theoretical results on polysilicon emitter bipolar transistors

Two types of polysilicon emitter transistors have been fabricated using identical processing except for the surface treatment prior to polysilicon deposition. The first type was given a dip etch in buffered hydrofluoric acid, which was intended to remove any interfacial oxide, while the second type was given an RCA clean, which was intended to grow an interfacial oxide of known thickness. Detailed electrical measurements have been made on these devices including the temperature dependence of the gain over a wide temperature range. The transistors given an RCA clean have gains approximately five times higher than those given an HF etch. In addition, the temperature dependence of the gain is different for the two types, with the HF devices exhibiting a much stronger dependence at high temperatures than the RCA devices. A detailed comparison is made with the theory and it is shown that the characteristics of the HF devices can largely be explained using a transport theory, while those of the RCA devices can be fully explained using a modified tunneling theory.     

位置敏感光电探测器

位置敏感光电探测器具有广泛的用途，介绍了器件的工作原理，输出信号的位置表达式及各种不同几何图形，等效电路，位置线性度和清晰度等参数性能，存在的缺点，以及不同几何结构的器件性能比较。     

单层介质膜全反射棱镜光学相位延迟器的设计

反射式光学相位延迟器件在光学工程中有着广泛的应用,本文从全反射和单层介质膜理论出发,研究了光学相位延迟随光线入射角和单层膜厚度的变化,可以看到通过适当的参数组合,几乎可以设计出各种实际需要的光学相位延迟器件,而且更为重要的是,这种相位延迟器件在实现其相位延迟时没有光能量损失,这在实际应用中非常有用和重要.     

High-efficiency operation of transferred-electron devices in the hybrid mode

Efficiencies up to 22% at peak-power levels of 60 W in X band have been obtained with transferred-electron devices. These efficiencies are in good agreement with values computed from hybrid-mode theory. A waveguide circuit which permits independent adjustment of the resistive and reactive components of the circuit impedance at the device-package terminals is described. This circuit provides a match for devices with widely different impedances. The close agreement between the theoretical and experimental values of efficiency indicate that both high material quality and an optimum impedance match between the device and the circuit have been achieved.     

A new approach to nonlinear analysis of noise behavior ofsynchronized oscillators and analog-frequency dividers

An original theory of phase noise in synchronized oscillators is outlined through the phase-locked loop (PLL) approach. The phase-noise spectrum obtained first by the analytical PLL theory and then by a simulator have been compared with very good accuracy. This new approach permits the best understanding of noise conversion in synchronized devices     

用于光纤阵列的Si-V型槽的制作

集成光学器件已在许多领域得到了应用，对所有的光学器件，光纤与芯片之间的耦合都是一大难题，这是因为耦合的对准精度要求十分严格。常用的耦合方法之一是用精确腐蚀的Si-V型槽作为集成光学器件尾纤耦合时光纤的固定夹具，V型槽的质量直接关系到耦合的成败。探讨了Si-V型槽制作的理论，尺寸设计及工艺。     

Performance and optimization of dipole heterostructure field-effecttransistor

Dipole heterostructure field effect transistors (dipole HFETs) have been fabricated in AlGaAs/GaAs. Doped p⁺⁺ and n⁺⁺ planes in the charge control AlGaAs layer form a dipole that creates a considerably larger barrier between the channel and the gate than in conventional heterostructure FETs. This leads to a sharp reduction of the forward-biased gate current in enhancement-mode n-channel devices, a much broader transconductance peak, and a higher maximum drain current in enhancement-mode devices. The authors also outline an analytical theory, supported by numerical modeling, for the optimization of device structures for both enhancement- and depletion-mode devices. This is supported by experimental results obtained from enhancement devices     

Computer-aided analysis of GaAs n-i-n structures with a heavily compensated i-layer

Current-voltage characteristics and space-charge distributions in an n-i-n structure have been numerically analyzed and compared with Lampert's theory. It is found that an effective resistivity in the low-voltage region depends on acceptor and trap densities and the length of an i-layer. The analytical model has been presented to estimate the effective resistivity and the onset voltage for current rise. The back-gating effect also has been analyzed in terms of a separation distance between devices and an acceptor density. To achieve a good isolation between two devices in GaAs IC's, it is suggested that a shallow acceptor density as well as a trap density must be larger than a critical value.     

Percolation dominated electron transport in Tetracyanoquinodimethane mixed 4,7-diphenyl-1,10-phenanthroline thin films

Highly conducting and electron transporting organic semiconductor tetracyano-quinodimethane (TCNQ) has been added to the well known electron transporting material 4,7-diphenyl-1,10-phenanthroline (BPhen) in various mixing percentages. Electron only devices exhibited a distinctive transition from low to high conductivity. The results have been found to be in good agreement with classical percolation theory with a percolation threshold of 3.8 wt.% and a critical exponent value of 1.3. This demonstrates the formation of a morphologically stable 2D percolating network that has been supported by AFM analysis. The composition thus formed indicates a promising electron injecting material for optoelectronic devices.     

Silicon optical modulators at 1.3-μm based on free-carrierabsorption

Silicon optical waveguide modulators, appropriate for operation in the 1.3-1.55 μm wavelength region, have been fabricated and their performance characterized at the wavelength of 1.3 μm. The modulator structures consist of p-i-n diodes integrated with silicon waveguides; device operation is based on free-carrier absorption. Modulation depths of -6.2 dB and response times less than 50 ns have been measured. Experimental results are compared with the p-i-n diode theory. It is argued that the device is suitable for integration with silicon electronics and silicon optoelectronic devices. The response times measured for the current devices may be improved by reducing the transverse dimensions of the p-i-n structure