An efficient algorithm for optimal allocation of wavelength converters in wavelength routing optical network

In a wavelength routing optical network(WRON),the optimal allocation of wavelength converters(WCs)is very important to minimize the number of WCs,enhance the fiber utilization,reduce the blocking probability,etc..In this paper,a novel simplified network model with shared WCs has been proposed.An effective algorithm for optimal allocation of shared WCs has been presented by using a revised Dijkstra algorithm and genetic algorithm(GA).The effectiveness of the revised algorithm was verified through the simulation on Nature and Science Foundation(NSF)net of USA.This revised algorithm can achieve blocking probability 36% less than the algorithm in previous work,and the calculating time of the minimum blocking probability can be reduced dramatically.     

光无线接入收发合一的光学系统设计

提出了一种用于光无线接入的光学系统设计方案。该系统采用偏振分光镜可实现收发合一 ,从而简化了设计 ,减小了光学系统体积。同时还对该光学系统性能进行了分析。结果表明 ,所提出的无线接入光学系统体积小、通信效率高 ,完全能满足接入的要求     

非相干光四波混频研究半导体光放大器超快过程

具体推导了相位共轭型非相干光时延四波混频信号强度随时间延迟的一般变化规律。结果表明：对于用有限线宽非相干光激发源非相干光时延四波混频信号强度随时间延迟的变化规律具有对称性，且强度峰与激发光场带宽成正比，与纵向弛豫速率成反比。这一结果为利用发光二极管作抽运源研究半导体光放大器及有源光波导超快动力学过程提供了理论基础。进而提出了用发光二极管结构的非相干光时延四波混频测量有源介质带间和带内载流子弛豫速率的有效方案。     

双折射对基于半导体光放大器的干涉型器件性能影响的模拟分析研究

分析了半导体光放大器中双折射对基于半导体光放大器的干涉型器件性能的影响，对基于半导体光放大器的马赫—曾德尔型波长转换器的理论计算表明，当半导体光放大器有双折射存在时，消光比不仅要比无双折射时的要低，而且还随着探测光的偏振态而改变，变化幅度可大于10dB。提出了减小双折射对干涉型器件影响的方案，并且分析了实现对增益和对相位变化同时具有偏振不灵敏的半导体光放大器的可能性。     

掺饵光纤激光器的自持脉冲

提出一种结构新颖且简单的环形掺饵光纤激光器，在较低的抽运参数条件下观察到了自持脉冲。就抽运参数、光纤环中单模光纤长度对输出激光脉冲特性的影响等进行了实验研究。结果表明，通过合适地调节激光器的有关参数可以实现对输出激光脉冲特性的控制。     

半导体光放大器环镜的非归零信号时钟分量提取

对基于半导体光放大器非线性环镜的非归零信号时钟分量提取进行了数值模拟和实验研究。不仅采用半导体光放大器的分段模型分别对简化方案和抽运一探测方案进行了2．5Gbit／s下的数值模拟，而且实验上采用这两种方案分别将2．5Gbit／s的非归零信号转换为包含其时钟分量的相应的伪归零信号。模拟计算结果与实验结果吻合得很好。实验和模拟结果均表明：采用简化方案时转换输出的伪归零信号所包含的时钟分量的强度小于采用抽运一探测方案的情况。10Gbit／s下的模拟计算结果表明在码型效应尚能容忍的前提下简化方案工作速率的上限小于抽运一探测方案。     

Hybrid Active-Passive Microwave Photonic Filter with High Quality Factor

A hybrid high quality factor （Q-factor） microwave photonic filter with a cascaded active filter and a passive filter is presented and experimentally demonstrated. The active infinite impulse response filter is realized by a recirculating delay line loop with a semiconductor optical amplifier, and a much narrower 3 dB bandwidth of response peaks can be achieved. A passive finite impulse response filter is realized by an unbalance Mach-Zehnder interferometer, and it is cascaded to select the desired filter frequencies and to suppress the intermediate peaks. Compared with the purely active filter scheme, the free spectrum range and the Q-factor of the hybrid structure can be doubled. Stable operation and a high Q-factor of 362 are experimentally demonstrated.     

基于环行腔激光器四波混频型可调谐波长转换的理论研究

建立了完整的基于半导体环行腔激光器四波混频型可调谐波长转换器的宽带理论模型.模型中考虑了半导体光放大器的材料增益谱、载流子的空间分布、光场的纵向空间分布和宽带放大自发发射等关键因素，并通过数值模拟，从理论上研究了这种波长转换器的各种性能与输入信号光功率、注入电流、输出耦合器的耦合比和环行腔激光器激射光波长的关系.理论上所得结论与文献中实验结果符合得很好. 关键词： 半导体环行腔激光器 四波混频 波长转换 放大自发发射     

两种烷氧基取代的聚对苯撑共聚物的光致发光性能

自Ｂｕｒｏｕｇｈｅｓ等采用聚对苯乙炔作电致发光器件获得成功以来［１］，人们已研究了各种荧光效率高、自吸收小的高分子材料的发光特性．为了调节高聚物发光材料的发光波长，提高其发光量子效率，还研究了不同发光材料在共混或共聚之后所表现出的新的发光行为［２～４...     

A Proposal and Demonstration for Photonic Generation of a Microwave Signal by Incorporating a Microring Resonator

A proposal for photonic generation of a microwave signal is presented by employing a dual wavelength erbiumdoped fibre ring laser. In the laser, a microring resonator is cascaded with a tunable bandpass filter to serve as a dual-wavelength selector, an unpumped polarization maintaining erbium-doped fibre is used as a saturable absorber. By replacing the microring resonator with a delay interferometer to verify the proposal, a wavelengthtunable dual wavelength single longitudinal mode laser is demonstrated, and a microwave signal at 10.01 GHz with a linewidth of less than 25 kHz is obtained by beating the two wavelengths at a photodetector.