对称结构光纤光栅耦合器及其应用

光纤光栅耦合器(FGC)具有光纤光栅良好的波长选择特性和光纤耦合器的多端口特点，易于实现全光纤的光波分插复用。光纤光栅耦合器主要有4种结构：基于M Z干涉仪的分离型、基于100％耦合器的非对称型、基于0耦合器的非对称型和基于100％耦合器的对称型。着重介绍对称结构光纤光栅耦合器的结构、工作原理和研究现状。提出了测试方案，并探讨了这种器件在大规模波分复用光纤传感器阵列中的应用。     

平面弯曲波导耦合器的特性分析

根据耦合模理论和弯曲波导耦合器的结构特点,对平面弯曲波导耦合器的特性进行了分析,结果表明弯曲波导耦合器的弯曲半径和最小间距两个可调变量,增加了波导器件设计的灵活性;同时由于等效耦合长度的调制作用使得弯曲波导耦合器在波分复用/解复用中比平行直波导耦合器具有更大的复用带宽;分析了弯曲半径和最小间距对弯曲波导耦合器复用带宽的影响,为实际波导器件的设计制作提供了一定的理论依据.     

面向稀疏波分复用系统的超大带宽硅基光子滤波器

大带宽光子滤波器被广泛应用于稀疏波分复用系统中,而在硅基芯片上实现结构紧凑、性能优良的超大带宽滤波器仍然是该领域研究的重点。提出一种基于光栅辅助反向耦合器的超大带宽硅基光子滤波器。利用窄波导更低有效折射率和更分散电场分布的性质,实现了带宽为92.9 nm、器件长度为250.6μm的超大带宽滤波器。该滤波器具有矩形度高、带宽大、损耗低等优势,能满足稀疏波分复用系统中解复用等需求。     

带有布喇格光栅的光纤失配耦合器的传输特性分析

本文利用模式耦合理论,分析了光纤失配耦合器在耦合区带有一个布喇格光栅后两光纤中基模场的传输特性,得到基模场发生耦合现象的条件及满足的方程。采用数值分析方法模拟耦合现象,并得出了带有布喇格光栅的光纤耦合器用于波分复用/解复用的最优化设计方案。     

带有布喇格光栅的光纤失配耦合器的传输特性分析(英文 )

本文利用模式耦合理论,分析了光纤失配耦合器在耦合区带有一个布喇格光栅后两光纤中基模场的传输特性,得到基模场发生耦合现象的条件及满足的方程． 采用数值分析方法模拟耦合现象,并得出了带有布喇格光栅的光纤耦合器用于波分复用／解复用的最优化设计方案．     

用三干涉臂马赫-曾德尔干涉仪制成的光纤密集型波分复用器

提出一种新型的光纤干涉仪 ,它是采用二个 3× 3单模光纤耦合器组成三光纤系统的马赫 -曾德尔 (Mach- Zehnder)干涉仪 ,当干涉仪的三条光纤干涉臂两两之间分别存在长度差Δ L和2Δ L时 ,干涉仪形成了一个波分复用间隔相等的三波分复用器 ,波分复用的波长间隔仅仅取决于ΔL的大小。实验样品的使用波段为 1.55μm,波长复用间隔为 1.6 nm,附加损耗为 0 .6 d B。     

阵列波导光栅波分复用/解复用器光谱响应效率的理论模型

基于单模光波导的本征模场分布,瑞利－索末菲衍射积分公式和天线原理的互易定理,给出耦合器中两个非接触平面光波导耦合特性的描述.基此,根据等光程差不等振幅多光束干涉的光场叠加原理,推导出新颖的阵列波导光栅波分复用/解复用器的光谱响应效率的解析函数表达式,这些表达式可为快速精确分析阵列波导光栅波分复用/解复用器的特性提供理论基础.同时,介绍了一个计算阵列波导光栅波分复用/解复用器特性的例子,给出其光谱响应度和信号通道串扰.     

单模光纤窄带波分复用器的研究

由组合波导理论出发，分析了超长耦合器合区光纤间的功率耦合特性以及器件的偏振特性，并提出了研制二段窄波分单模光纤波发复用器的新方法，在研制常规耦合器的工艺基础上，先后研制成功１３１０ｎｍ或１５５０ｎｍ单窗口窄带波分复用器及１３１０ｎｍ或１５５０ｎｍ双窗口等三种复用间隔约１４ｎｍ的窄带波分复用器，其波长隔离度大于２０ｄＢ，具有２～３ｎｍ的带宽，偏振灵敏度小于０．１ｄＢ，附加损耗小于０．５ｄＢ，这些参数     

太赫兹双空芯光纤定向耦合器

设计了一种低损耗太赫兹双芯光子带隙光纤定向耦合器.采用全矢量有限元法对光纤的耦合特性、损耗和色散进行了理论分析.结果表明,这种光纤定向耦合器在1.55-1.80 THz范围内耦合长度小于1.8 cm,能够实现0.07THz范围内窄带耦合,且其损耗系数低于0.02 cm-1.这种耦合器将在太赫兹窄带滤波、波分复用、开关和偏振分离等技术中有潜在应用价值.     

全光纤密集型波分复用器

分析了全光纤Ｍａｃｈ－Ｚｅｈｎｄｅｒ结构的功率谱特性，并利用自行设计的耦合器拉锥设备，研制成功最小波长复用间隔为０．４５ｎｍ的密集型波分复用器。该类器件具有附加损耗低，偏振不灵敏和较好的温度及机械稳定性等特点。     

一种分布反射型大容量WDM星形单跳网

针对现有分布反射型WDM星形单跳网结构上存在的问题,本文提出了一种新的分布反射型WDM星形单跳网.这种WDM网络不仅抗毁性能好、可靠性高,而且网络容量大、组网灵活性强,可实现网络的在线扩容、升级,为未来大容量WDM局域网提供了一个理想的选择.文章首先论述了该分布反射型大容量WDM星形单跳网的结构,其次分析了网络中各个节点之间的通信,进而计算了网络所支持的最大节点数,最后对全文进行了总结.     

Designing an all-optical packet filtering module for WDM broadcast-and-select star networks

An all-optical packet filtering module for WDM broadcast-and-select star networks is introduced. At each time instant, only one packet per wavelength is allowed to pass to the star coupler. Therefore, collisions are avoided and the network performance is improved. The proposed module is based on the use of optical logic circuits for controlling the passing of the transmitted packets to the star coupler, without the need of optical to electronic translation or electronic processing of the network feedback information. In this way, the processing time is drastically reduced, while the need for slowly tunable optical filters is eliminated. Furthermore, due to the all-optical nature of the network hub, the reliability of the system is improved.     

波长重用-扩大基于单纤连接节点的WDM星形单跳网容量

针对可利用的有限信道波长数对基于单纤连接节点的WDM星形单跳网容量限制问题,本文提出了一种有效的解决方案-波长重用.根据该方案,在信道波长数一定的条件下,至少可使网络所支持的节点数-网络容量扩大一倍;在网络节点数不变时,则可大大减少网络节点的排队时延,缓和网络中各通信节点对数据信道波长使用权的竞争矛盾,使网络吞吐量增加1～3倍,有效地改善网络性能.本文首先论述了该基于单纤连接节点的波长重用WDM星形单跳网结构,接着分析了网络的波长重用特性,进而对所要求的光放大器增益和输出功率进行了计算;最后计算了网络的最大节点数和最大信道波长数.     

Algorithm for Scheduling Variable-Length Messages in WDM Networks

In this paper, we develop and analyze a simple algorithm for scheduling variable length messages in WDM networks with a passive star coupler. We base our schemes on a star topology with centralized control and use a scheduling algorithm similar to the process management in UNIX system. Every node and message have a scheduling priority associated with them. By comparing our algorithm with random select algorithm, we find that significant improvement in performance can be achieved with very little extra cost.     

Fused biconical tapered fiber-optic devices: Application to data buses

The technology of fiber-optic couplers based on fused biconical tapered structures is reviewed, and the linear and star data-bus configurations that can be constructed using these couplers are discussed. A useful network topology for interconnecting star couplers using the hybrid transmission-reflection star coupler is also proposed. This network configuration has the advantage of requiring significantly less optical fiber than networks employing a single transmission or reflection star.     

Fused biconical tapered fiber-optic devices: Application to data buses

Abstract

The technology of fiber-optic couplers based on fused biconical tapered structures is reviewed, and the linear and star data-bus configurations that can be constructed using these couplers are discussed. A useful network topology for interconnecting star couplers using the hybrid transmission-reflection star coupler is also proposed. This network configuration has the advantage of requiring significantly less optical fiber than networks employing a single transmission or reflection star.     

Bi-wavelength two dimensional chirped grating couplers for low cost WDM PON transceivers

We propose and demonstrate a bi-wavelength two dimensional (2D) waveguide grating coupler on silicon-on-insulator which has efficient coupling of optical light with two-wavelength bands independently between standard optical single mode fibers and nanophotonic waveguides. The details of design are described and the measurement results as well as system performance are experimentally characterized. The bi-wavelength grating coupler can be used as wavelength-division-multiplexing (WDM) splitter/combiner for monolithically silicon integrated transceivers, potentially meeting the low cost requirements for future WDM passive optical network (PON).     

平面波导型对称星型耦合器的优化设计

通过有限差分波束传播法(FD-BPM)研究了N×N平面波导型星型耦合器的优化设计思想和方法,并通过17×17星型耦合器的模拟设计证明了它的可行性.给出了在输出端引入辅助波导的方法,以提高输出波导阵列的均匀性.并通过模拟计算,分析了圆心缩入程度和锥形区的形状对输出结果的影响.此法也同样适合于N值更大的星型耦合器.     

Effect of Four-Wave Mixing on Optimal Placement of Optical Amplifier in WDM Star Networks

In this article, the effect of four-wave mixing (FWM) and amplified spontaneous emission (ASE) noise on WDM optical star networks has been investigated. Analysis for the evaluation of probability of error has been carried out (a) when only FWM is present and (b) when both FWM and ASE noise are present. Numerical results are presented in the graphical and tabular forms for the practical values of parameters. Finally, optimal location of the amplifier in the network has been identified as being before the star coupler preceding the receiver.     

Effect of Four-Wave Mixing on Optimal Placement of Optical Amplifier in WDM Star Networks

In this article, the effect of four-wave mixing (FWM) and amplified spontaneous emission (ASE) noise on WDM optical star networks has been investigated. Analysis for the evaluation of probability of error has been carried out (a) when only FWM is present and (b) when both FWM and ASE noise are present. Numerical results are presented in the graphical and tabular forms for the practical values of parameters. Finally, optimal location of the amplifier in the network has been identified as being before the star coupler preceding the receiver.