衍射光栅技术进展

具有精确刻槽的衍射光栅是基本的光学元件之一。这些精细的周期结构可以将入射光中包含的各个单一波长的光分开。光栅对于物理学家确定原子结构,天文学家计算星体的化学成分和星系的转动是必不可少的。它的应用范围越来越广泛,其中光栅应用发     

长周期莫尔光栅的理论研究

长周期光纤光栅作为一种损耗型的带阻滤波器，在光纤通信和光纤传感器领域有着广泛的应用。结合长周期光纤光栅的传输特性，利用传输矩阵法对多种长周期莫尔光栅的透射谱进行了理论模拟。分析结果表明，莫尔光栅技术在制作高性能的相移长周期光栅和变迹长周期光栅上有着很好的应用前景。     

光纤光栅写入的最新进展

光纤光栅写入的发展在近年来十分迅速,各种写入法层出不穷,文中综述了光纤光栅写入技术在近一两年的最新发展     

光纤光栅传感技术及其应用

本文从光纤光栅的写入技术、光纤光栅的特性、光纤光栅的调谐技术、光纤光栅的传感原理几个方面对光纤光栅技术及其应用，尤其是Bragg光纤光栅在智能结构中的应用作了较为详细的综述与探讨，并描述了光纤光栅的发展及其现状。     

光纤光栅级联时延特性的研究

理论分析了啁啾光栅级联应用于波分复用(WDM)系统中的时延特性，时延纹波随光栅级联个数的增多而增大，随级联光栅的相邻光栅波长间隔增大而减少。分析采用8阶高斯适当切趾可以减少光栅间相互影响。对理论分析进行了实验验证。     

多级位相光栅的设计

本文研究了多级位相光栅的设计原理，给出了几组不同陈列数的多极位相光栅的设计参数。结果表明所设计的光栅各级衍射光强均匀分布且具有较高的衍射效率。     

基于匹配光栅对的传感解调装置

提出并实验了一种新颖的匹配光栅对解调方案，受压电陶瓷驱动，解调光栅对传感光栅反射光波进行波长扫描，将传感光栅布拉格反射波长的漂移变为解调光栅透过的负脉冲在时域中间隔的变化进而确定待测应变量的大小。系统传感灵敏度的实验值为94．417με／ms，具有-100～700με的传感测量范围。     

光栅常数的一种简便测量方法

本文给出利用Ｈｅ－Ｎｅ激光束通过光栅所产生的夫琅和费衍射，测定光栅常数的一种简便方法。     

应用密集波分复用技术的光接入网

密集波分复用 (DWDM)和光接入网 (OAN)技术被公认为是最有前途的两种光传输技术 ,而结合两者的 DWDM OAN为接入网的发展提供一个新的技术选择 ;分析了两种主要的 DWDM OAN技术方案 ,指出两者涉及的关键技术 ,并提出采用光纤光栅作为 DWDM OAN关键元件的设想     

第三代DWDM光网络接近实用

在城域网（MAN）和局域网(LAN)中,虽然带宽和网络容量持续地增长,但是在市区内人们仍然面临着严重挑战。在这里,为了提供G比特级带宽和灵活的网络配置,业务提供商不得不采用传统的SONET设备和第二代DWDM设备。基于全光DWDM设备的第三代网络将能够动态地配置和管理网络,为业务提供商提供迫切需要的解决方案。用户对供应速度的要求速度不仅仅指带宽,而且也指提供服务的速度,而且两者都日趋重要。用户所需要的是大容量带宽和及时地提供服务。因此,剩下的问题是谁能够提供和什么时候能够提供这些业务。谁能先提供宽带业务,谁…     

Optical metropolitan DWDM networks an overview

The paper deals with the subject of how to build a core network in the current technology scenario. We start with an overview ofwhat we consider a core network, not in an abstract way but referring to real country situations, and pointing out the differentaspects conditioning its realisation – population distribution, territory shape, traffic characteristics. In the next section asummary of different network topologies is presented and briefly analysed – rings, meshes, loosely or tightly interconnected,with particular attention to the resilience aspect in case of faults. The following section is dedicated to a short presentation of thecurrent technology scenario and how it reflects on the network elements (NEs) offered on the market (OXC, OADM, PXC, etc).Finally, the question is posed: “What is the best way to implement a core network?” with the conclusion being that there is nosingle answer – each situation must be pursued on a case-by-case basis. This paper describes some important aspects of next-generation metropolitan networking, with special focus on market driversand applications, upcoming standards like GFP and GMPLS, required functionalities like optical switching and protection, and ageneric view on a next-generation platform.     

Routing scalability in multi-domain DWDM networks

This paper studies routing scalability in multi-domain DWDM networks. Although inter-domain provisioning has been well studied for packet/cell-switching networks, the wavelength dimension (along with wavelength conversion) poses many challenges in multi-domain DWDM settings. To address these concerns a detailed GMPLS-based hierarchical routing framework is proposed for multi-domain DWDM networks with wavelength conversion. This solution uses mesh topology abstraction schemes to hide domain-internal state. However related inter-domain routing loads can be significant here, growing by the square of the number of border nodes. To address these scalability limitations, improved inter-domain routing update strategies are also proposed and the associated performance of inter-domain lightpath RWA and signaling schemes studied.

Application-aware protection in DWDM optical networks

Fast recovery time and reduced resource utilization are the two main criteria for determining the quality of survivability mechanism. Now, it is well known that link-based protection and path-based protection provide, respectively, a short recovery time and reduced use of resources. To benefit from the both of these saliencies, we propose in this paper to use these mechanisms simultaneously. Indeed, demands mandating shorter recovery time will be protected using link-based protection. Meanwhile, other demands (e.g., no-critical) will be protected using path-based protection. Simulation results show that the proposed solution achieves a good trade-off between resource utilization and recovery time.     

光纤智能结构中Bragg光栅的DWDM检测

光纤Bragg光栅传感器以其优越的性能是最有希望应用于光纤智能结构中的传感器。基于DWDM原理与技术提出了在光纤智能结构的应用中检测光栅波长位移的DWDM方法，进行了实验研究和相关讨论，实验表明在较大范围内波长位移与轴向应变呈线性．为光纤光栅智能结构的实用化推广打下基础．     

DWDM系统中均匀光纤光栅的设计

分析了用于DWDM系统均匀光纤光栅反射特性与光栅、光刻条件的关系;给出了用于DWDM系统中的光纤光栅的设计原理、方法及确定光栅参数的流程.采用高斯光束和均匀相位模版,用二次曝光技术,有效消除了均匀光纤光栅的反射谱旁瓣,所设计和刻制的光栅完全满足DWDM系统的要求.     

从OFC2001会议看DWDM全光网中的无源器件

概述了在2001年OFC会议上出现的新型光无源器件，介绍了光无源器件的最新进展，着重分析了几种用于DWDM光网络中的最新型光无源器件的工作原理和结构。     

城域网:DWDM应用的下一个撒手锏?

前一段时期,DWDM技术主要用于长途骨干网。今天,由于电信运营综合楼（telecom carrier hotel）的普及和永无止境的带宽需求,城域网极有可能成为DWDM技术的又一个撒手锏应用。全新的DWDM系统,不仅组合了TDM技术的优势和WDM无以伦比的扩展能力,而且还能够提供SONET级别的可靠性和业务的快速提供能力。TDM技术的每一次进展（从OC-48到OC-192、从OC-192到OC-768）都极大地扩展了基于WDM技术的系统的传输容量。相比之下,SONET系统的扩展还是无法超越传送设备中最初安装的光模块的速率限制。城域网的新面貌仔细观察一下当…     

Virtual loops in power-equalized transparent DWDM networks

In wavelength-routed DWDM (Dense Wavelength Division Multiplexing) networks, more and more DPEs (Dynamic Power Equalizers) are being implemented in optical crossconnects or add-drop multiplexers for the purpose of maintaining uniform power on working wavelengths. However, the resultant power correlation among equalized channels, when provided with appropriate link gain settings and channel routes, may form power-interactive virtual loops on which signals can experience continuous power deterioration, iteration by iteration. This paper illustrates how such virtual loops may be formed, and what can be done to avoid them by properly designing the network. We also explain the QoS (Quality of Service) threat posed by virtual loops that can be deliberately created by malicious attackers to result in a network-scale service disruption. Guidelines on improving the network robustness against such attacks are presented as well.