取样光栅的反射谱特性及其应用

本文基于取样光栅的独特反射谱特性，对其作为光子器件如DBR撒光器、波分复用／解复器和光插分复用器的结构图作了探讨。通过比较得知，用取样光栅构成的新型光子学器件比用单纯的光纤光栅构成的光子学器件在未来的密集型波分复用(DWDM)光纤通信系统中更有实用价值。     

光纤的紫外曝光引起的背景损耗

在密集波分复用(DWDM)系统中进行多信道色散补偿时,需要把多个光纤光栅串联在一起使用,这样连接在后面的光纤光栅的插损会因为背景损耗的存在而随着光纤光栅数量的增加而增大,尤其是波长较多的时候,接在最后的信道的插损会显著增大,这将制约光纤光栅的最大连接数。通过实验探讨了光纤的紫外曝光造成的背景损耗对串联的窄带啁啾光纤光栅的影响以及对光纤光栅最大连接数的限制。     

基于级联光纤光栅的透射色散补偿

分析了光纤光栅的色散特性,介绍了利用均匀光纤光栅透射色散特性进行色散补偿的原理,对级联光纤光栅用于波分复用(WDM)系统多信道色散补偿进行了数值模拟和分析.结果表明,通过选择适当的光纤光栅参数,级联光栅能够对WDM系统中由于常规光纤而色散展宽的光脉冲进行有效的色散补偿.     

相移光纤光栅传输谱的研究

相移光纤光栅可作为密集波分复用（DWDM）系统中的解复用器，相移的大小，位置和相移点的多少对该解复用器的性能有重要影响，应用传输矩阵理论分析了相移光纤光栅的相移大小，相移位置不同和多点相移对光纤光栅传输谱的影响。     

DWDM光纤通信系统的光纤光栅色散补偿技术

分析研究了各种用于DWDM(密集波分复用)系统色散补偿的光纤光栅的原理、性能和制作工艺，根据它们的结构特征进行了详细的分类，进一步分析比较了它们各自的优缺点。     

取样光栅的反射谱特性及其应用

本文基于取样光栅的独特反射谱特性,对其作为光子器件如DBR激光器、波分复用/解复器和光插分复用器的结构图作了探讨.通过比较得知,用取样光栅构成的新型光子学器件比用单纯的光纤光栅构成的光子学器件在未来的密集型波分复用(DWDM)光纤通信系统中更有实用价值.     

CWDM技术及其在城域传送网中的应用

1 CWDM系统技术 CWDM(Coarse WDM)即粗波分复用系统是通过利用合波器将在不同光纤中传输的波长集中到一根光纤中传输来实现。在链路的接收端,利用分波器将分解后的波长分别送到不同的光纤,接到不同的接收机。CWDM的信道间隔为20nm,而DWDM的信道间隔从0.2nm到1.2nm,所以相对于DWDM,CWDM称为粗波分复用技术。     

全光纤DWDM器件的研制

介绍了在密集波分复用系统中使用的一种全光纤波分复用解复用器件的原理,分析了第二个耦合器耦合比对信道隔离度的影响,给出了制作全光纤密集波分复用解复用器件的实验数据。     

LabVIEW应用于DWDM系统中的光纤光栅设计

分析了用于DWDM系统中的光纤光栅的设计原理，采用LabVIEW6.0确定光栅参数，给出了具体的软件算法流程及其实现的方法，给出采用二次曝光技术抑制旁瓣消除邻信道串扰的方法，所设计和刻制的光栅安全满足DWDM系统的要求。     

级联非平衡Mach—Zehnder干涉仪型复用器特性分析

本文分析了非平衡马赫－曾德干涉仪的特性,设计和讨论了多级级联非平衡马赫－曾德干涉仪型密集波分复用／解复用器,对其光谱特性、信道谱宽和隔离度进行了模拟分析,结果表明利用光纤光栅来提高信道隔离度的结构可以满足系统需要。这种结构复用／解复用器可用于至少16路或32路的密集波分复用系统中。     

Metropolitan DWDM: a dynamically configurable ring for the KomNetfield trial in Berlin

We present the system concept of a dynamically configurable all-optical add/drop multiplexer for metropolitan wavelength division multiplex rings using dense channel spacing (DWDM). We first outline the essential network requirements. Subsequently, an optical system concept is presented that meets these requirements. In the network elements, innovative all-optical switching technology is employed. Tunable fiber Bragg gratings that perform routing functions by wavelength filtering are discussed in more detail. The system is laboratory-tested. It has been installed in Berlin for a multi-vendor field trial within the German research program “KomNet.” Three optical add/drop multiplexers form a dynamically configurable Metro DWDM ring. Metro DWDM accommodates high bandwidths: a metropolitan ring that provides 0.8 terabit/s ring capacity has been demonstrated. Furthermore, Metro DWDM can provide optically transparent channels enabling the transport of various data formats simultaneously, e.g., SONET/SDH and Gigabit Ethernet. Conversion to a standard format becomes obsolete. The all-optical add/drop multiplexer (OADM) presented provides both manual and dynamic configuration. The system concept of the OADM is developed starting with basic metropolitan DWDM network requirements. The features of the DWDM ring are described, followed by a presentation of the system concept of the flexible OADM. Our focus is on dynamic configuration techniques. Since tunable fiber Bragg gratings are promising components for dynamic optical channel switching, this technology is treated in more detail     

Reconfigurable OADM and OXC designed by a new optical switch

A new dynamically selective optical add/drop multiplexer (OADM) and optical cross-connect (OXC) configuration for dense wavelength division multiplexed (DWDM) networks are proposed. The selective devices are based on fiber Bragg gratings (FBGs), single-sided micro-mirror optical switches (OSWs), and optical circulators (OCs). They are flexible, expandable, and high capacity in DWDM networks if the basic units are cascaded in series. In this paper, fiber collimators in coupling are analyzed in order to characterize the insertion loss and output power equalization in OADM and OXC. “Off-the-shelf” DWDM communication products are used for analysis; as a result, the main insertion loss in the system comes from circulators while the maximum insertion loss deviation comes mainly from FBGs and micro-mirrors. As compared to the other existing reconfigurable OADMs and OXCs, the number of mirrors in the optical switch could be dramatically reduced. The reliability of optical switch operation, therefore, can be enhanced.     

Fiber-grating add–drop reconfigurable multiplexer with multichannel using in bi-directional optical network

A bi-directional reconfigurable scheme of multichannel-selective optical add–drop multiplexer (OADM) is proposed in this paper. With only small wavelength channel tuned range, the proposal applies fiber Bragg gratings (FBGs) and multiport optical circulators (MOCs) to build a bi-direction reconfigurable OADM which can deal with full channels without the receiving signal having wavelength-interleaved. Moreover, it is easier and more flexible to extend wavelength channels by cascading additional FBGs. The magnitudes of homodyne and heterodyne crosstalks are analyzed for evaluating the performance of the proposed BOADM. Also, the power equalization of each signal in the add–drop and output ports is managed properly by implementing filters. As a result, the BOADM will be found in wide applications in dense wavelength-division multiplexing (DWDM) optical networks and in multiwavelength crossconnects (WXCs).     

布拉格光栅辅助型上下话路滤波器的实验制作

采用波长为248nm的紫外光,在由标准单模光纤和自制的高掺锗光敏光纤熔融拉锥制作的2×2光纤失配耦合器上写入光纤光栅,实现了全光纤布拉格光栅(FBG)辅助失配耦合器型上下话路滤波器,并测试了器件的传输特性,器件的插入损耗和回波损耗分别为6.74dB和-18.84dB。用10Gbps的光信号进行了传输实验,分别测试了下话路前、后信号的眼图。与输入信号相比,下话路信号的信噪比从10.04dB降低到了9.27dB,信号的消光比从8.89dB降低到了4.68dB。     

Large-band periodic filters for DWDM using multiple-superimposed fiber Bragg gratings

The tight specifications of dense wavelength division multiplexing (DWDM) filters are challenging for any available technologies. In this letter, periodic transmission filters based on superimposed chirped fiber Bragg gratings are designed to have flat amplitude response and nearly constant in-band group delay. These filters should prove to be useful as interleavers and mux/demux filters in DWDM systems.     

Investigation on reflection spectra of chirped and phase-shifted fiber Bragg gratings

The characteristics of chirped and phase-shifted fiber Bragg gratings have been investigated by the use of transfer matrix formulation. While the characteristics of a chirped and phase-shifted fiber Bragg grating are the same as those of non- chirped one in some important aspects, both the reflection and transmission windows of a chirped and phase-shifted fiber Bragg grating can be broadened in a wide range. Therefore, chirped and phase-shifted fiber Bragg gratings will have applications in WDM or DWDM optical communication systems. The work in this paper can be used to design the new devices based on chirped and phase-shifted fiber Bragg gratings.     

一种基于光纤Bragg光栅的全光纤分/插复用器

研制了用于ＷＤＭ全光网的全光纤型分／插复用器,由两个相同的光纤环行器和串接其间的光纤Ｂｒａｇｇ光栅组成。其中光纤Ｂｒａｇｇ光栅是用紫外光直写方式在普通单模光纤上制成。文中给出了该复用器的上／下路端口隔离度和信道插入抽耗等主要测量结果。其特点是结构简单,可实现信道波长再利用,从而提高网络的灵活性。     

Design and Realization of Uniform Fiber Bragg Grating Used in Dense Wavelength Division Multiplexing Systems

Relation of optical properties in a uniform fiber Bragg grating(FBG) with its grating parameters and the laser beam engraving conditions is analyzed.The principle and metod for designing the uniform FBTG used in dense wavelength divison multiplexing (DWDM) system is given,By adopting the double exposure technique,with a univform phase mask and Gaussian laser beam,the uniform FBG used in DWDM system is designed and engraved,whose bandwidth of the main relection band is about 0.4 nm and 0.7 nm at -5dB and-25dB respecively.     

Novel add/drop filters for wavelength-division-multiplexing optical fiber systems using a Bragg grating assisted mismatched coupler

We have demonstrated a novel add/drop filter for use in wavelength-division-multiplexing (WDM) optical fiber systems based on a Bragg grating assisted mismatched coupler. The device is potentially easy to fabricate and stable, because it is not interferometric, unlike all similar devices demonstrated so far, and, therefore, does not need fine tuning of the interferometers during fabrication and does not have to maintain the balance of the interferometers during its lifetime.