共查询到19条相似文献,搜索用时 284 毫秒
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稀疏波分复用技术(CWDM,CoarseWavelengthDivi鄄sionMultiplexing)最初用于多模光纤中传输数字视频信号。当时Quante公司推出了一个工作在800nm窗口、每信道140Mbit/s速率的四波系统,并应用在有线电视的广播链路中。而随着城域网市场的发展,稀疏波分复用技术正逐渐显现出其在系统成本、性能及可维护性等方面的优势。目前,该技术被定位于城域网传输平台中的业务汇聚层,它与密集波分复用DWDM的区别主要是:CWDM载波通道间距较宽,其波长间隔为20nm;DWDM的波长间隔在1郾6nm以下,同一根光纤上CWDM复用的波长数要… 相似文献
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可调谐光纤滤波器技术是波分复用系统的关键技术之一,对于发展全光通信网络和光纤传感具有极其重要的意义。提出了一种基于大芯径的多模光纤可调谐带阻滤波器,其制作方法是将包层/纤芯直径为125/105μm的特种多模光纤通过单模光纤接入光纤系统,实现单模-多模-单模(SMS)光纤结构,并使一端单模光纤与多模光纤熔接,另一端只是共轴对接而不焊接。在多模干涉原理的基础上,利用该结构对应变的敏感性实现可调谐光滤波。该可调谐滤波器的调制和解调借助于放大自发辐射(ASE)宽谱光源和光谱分析仪(OSA)实现。详细给出了该滤波器的理论仿真分析,并实验证实了该方案的有效性。 相似文献
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波分复用技术在HFC网络中的应用方式研究 总被引:1,自引:0,他引:1
文章研究了波分复用(WDM)技术在混合光纤/同轴电缆(HFC)网络中的应用方式.着重对密集波分复用(DWDM)技术和粗波分复用(CWDM)技术在HFC网络的下行方向和上行方向的应用方式进行了研究.研究结果表明,DWDM技术适用于HFC网络的下行方向,可以延长HFC网络的传输距离;CWDM技术适用于HFC网络的上行方向,可以增加HFC网络的上行带宽.利用WDM技术可以实现HFC网络的双向传输. 相似文献
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城域网和接入网发展需要的低水峰单模光纤 总被引:1,自引:1,他引:0
Shasgu kant Harish Taneja Sudipta Bhaumik Abhay Arora 《光通信研究》2005,(4):42-45
密集波分复用(DWDM)的出现扩大了长途传输网的容量,但是DWDM技术的复杂性和使用了昂贵的器件,限制了DWDM在城域网的应用.最新研制的光纤,其在整个宽工作带,包括在(1 380±3) nm上都具有低水峰.低水峰光纤与粗波分复用(CWDM)系统比用标准单模光纤(SMF)的同一系统所用的信道间隔宽33%.经过恶劣的环境试验证明,低水峰光纤具有稳定的抗氢气引起的衰减性能,可确保现场安装的低水峰光纤光缆长期可靠地工作.由于低水峰光纤具有优异的弯曲敏感性,使其与最近研制的宽带接入技术,即所谓的光纤到驻地(FTTP)完全相适应. 相似文献
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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。 相似文献
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设计了一种基于MEMS技术的可调谐光学滤波器,它通过光栅将输入的宽带光信号色散展开,以一个MEMS扭镜选择将对应滤波器通带的光信号反射至输出端,从而实现光学滤波和波长调谐功能。滤波器的输入端采用单模光纤,输出端采用多模或者少模光纤,可以实现窄带且平顶的通带特性。经过参数优化,仿真分析得结果显示,采用多模/少摸光纤输出的两种滤波器,其0.5 dB和25 dB带宽分别为0.95 nm/0.29 nm和1.39 nm/0.69 nm,分别满足100 GHz和50 GHz信道间隔的DWDM系统要求。由于输出端采用多模或者少摸光纤,从该滤波器输出的光信号不能继续在单模光纤中传输,只能由光探测器接收,因此该滤波器一般应用于全光网络节点中的下载端口。 相似文献
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CWDM关键技术及应用 总被引:2,自引:1,他引:1
张成良 《电信工程技术与标准化》2003,(7):29-31
本讨论CWDM特点、波长选择、光纤类型等关键技术,并对CWDM和DWDM进行详细比较,最后对CWDM的应用和发展予以了展望。 相似文献
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波分复用(WDM)是充分利用光纤容量的技术,是下一代全光网络的基础,因此WDM仍朝大容量方面发展,粗波分复用(CWDM)与密集波分复用(DWDM)在技术上具有相同的原理,而主要特征是在容量相同时前者成本比后者低。CWDM在技术上有两个特点,一是不使用光放大器,这样导致传输距离短,但也勿需考虑DWDM中的色散和非线性效应。二是可以采用无致冷激光器,这是使成本低廉的主要原因。CWDM一般应用在城域边缘网,也会用在一些接入网的连接上以节省光纤。 相似文献
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Long haul optical networks have been on focus for more than two decades. With the advent of dense wavelength division multiplexing technology, optical long haul fiber networks have been so successful in delivering an unprecedented amount of bandwidth that they outperformed the traffic deliverability from/to the access network by orders of magnitude. The reason was a cost-efficiency mismatch; long haul ultra-high bandwidth networks can take advantage of state of the art and costly technology, which cost-sensitive access networks cannot. The result was an unbalanced traffic flow from/to access points to the network if one compares the aggregate flow of the long haul network with that of the access. Nevertheless, over the last decade technology at the access advanced and new standards have been developed so that in the access layer of the overall communications network the focus has shifted onto fiber optic access again. Thus, in the optical regime, two proposals have prevailed. One uses a time division multiplexing (TDM) scheme over a single wavelength and a comprehensive timing protocol, and the other uses coarse wavelength division multiplexing (CWDM) technology. Each technology has advantages and disadvantages, and the one attempts to address the disadvantages of the other. In this paper we describe a hierarchical CWDM/TDM passive optical network (PON). Our access network architecture is scalable, it is flexible to accommodate one of several topologies simultaneously, and it delivers any type of payload, synchronous and asynchronous that spans from DS0 to Gbps. We discuss the bandwidth flexibility, versatility, resiliency and cost efficiency of the access network. We also demonstrate that our network can deliver payload to more than 16,000 end-users using simple and existing optical technology. Thus, if one considers cost per bandwidth or per user, the cost-efficiency outperforms any previous PON access network. Moreover, we provide simulation results to support the viability of our network architecture. 相似文献
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We propose a novel multiple-input multiple-output (MIMO) scheme over multimode fiber, acting as a distributed random code generator fed by spatial codes, using silicon photonics in the transmitter and maximum-likelihood (ML) electronic detection in the receiver, providing an alternative to coarse wavelength division multiplexing (CWDM) for implementation of ultrahigh speed parallel transmission over short-range optical interconnects. The optical MIMO system utilizes mutually coherent transmission and conventional direct detection with one-bit quantization, facilitating cost-effective application to 100 Gb/s links over < 50 m. 相似文献
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Semiconductor laser mode partition noise (LMPN) can impair analog optical systems, but this phenomenon has not previously been well-characterized. Theoretical expressions for the noise spectra that result when light from a nearly single-mode or strongly multimode semiconductor laser is passed through a length of dispersive optical fiber are presented and have been tested experimentally. A widely used model is found to greatly overestimate the partition noise of a DFB laser; a model for the strongly multimode case is found to match experimental results for a multimode laser. It is observed that partition noise can be significant even for multimode lasers operating near the fiber dispersion minimum 相似文献
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A 10-Gb/s transmission experiment has been performed on multishell multimode fiber Bragg gratings. The device can simultaneously serve as wavelength filter and mode selector and is compatible with conventional graded refractive index multimode fiber (MMF) components. This could be a promising technology for wavelength-division multiplexing and mode diversity in practical MMF-based optical access networks. 相似文献
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为改善短距离、低成本多模光纤RoF链路性能,需要对多模光纤中的重要限制因素—模式噪声进行分析,并寻找降低模式噪声影响的方案。首先分析了模式噪声的产生条件,建立了多模光纤RoF链路中模式噪声的数学模型,通过模型可以得出激光器频率啁啾越大、调制深度越低、光电二极管检测面积越小输出射频信号载噪比越小。可以通过降低激光器频率啁啾,增大调制深度和光电二极管检测面积来改善系统性能。 相似文献
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Chromatic dispersion effects on LED-based optical fiber systems are calculated as a function of transmission length and the LED central wavelength. The computer analysis includes the filtering effects of water absorption which reduces the spectral width of LED signal pulses. We show that the basebandwidth of multimode fiber systems can be significantly increased by offsetting the LED central wavelength above the wavelength at which minimum chromatic dispersion occurs in the fiber medium. Additional bandwidth degradation due to modal dispersion effects are not considered. However, the combined effects of optical loss and chromatic dispersion are used to calculate upper limits for repeater spacings in possible multimode wideband systems. 相似文献
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《Lightwave Technology, Journal of》2008,26(15):2396-2408
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Md. Nooruzzaman Halima Elbiaze Raja Zahilah Osanori Koyama Makoto Yamada 《Photonic Network Communications》2014,28(3):237-250
Coarse wavelength division multiplexing (CWDM) network has proven to be promising lower cost network architecture for a significant cost advantage over dense wavelength division multiplexing due to the lower cost of lasers and the filters used in CWDM modules. A compatible amplifier module having bidirectional amplification capability was deployed for introducing inside stackable reconfigurable optical add/drop multiplexers in realizing large-scale CWDM networks. The amplifier module for use in the bidirectional IP transmission confirmed that the insertion losses of the nodes and the losses of the fibers connecting the nodes can be compensated effectively, allowing the network administrator to increase the number of nodes and fiber length of the network. However, the noise generated from the amplification due to amplified spontaneous emission must be considered in network design issues. In this paper, optical power penalties due to the bidirectional amplification were estimated by conducting experimentation on minimum detectable power of optical transceivers. After analyzing the power penalty issue, an IP-over-CWDM ring network was implemented and the performance of network was evaluated by monitoring the power and packet transmissions before and after the amplifier module was turned on. 相似文献