• 中央环保督察“回头看” 发现两起虚假整改案例 2019-06-25
  • 太平财险湖北分公司成功续保东风乘用车财产险项目 2019-06-25
  • 壮观!150余位画师共绘梵高《星月夜》 2019-06-22
  • 蔡榆的专栏作者中国国家地理网 2019-06-22
  • 弘扬红船精神 当好勇立潮头城建排头兵 2019-06-22
  • 中央和国家机关“建功新时代 岗位作贡献”br劳模精神宣讲报告会在京举行 2019-06-18
  • 最高人民法院再审顾雏军案 2019-06-16
  • 窃贼落网瞒余罪 出狱当天又被抓 2019-06-15
  • 烟 雾谈资中国国家地理网 2019-06-15
  • 新西兰宣布对外国游客征税 称让游客作贡献“非常公平” 2019-06-11
  • 规范二手交易平台须多方给力 2019-06-10
  • 看见什么有用?[猜想] 2019-06-10
  • 女性之声——全国妇联 2019-06-09
  • 王小东周红波现场检查服务“两会”工作 2019-06-09
  • 而其实,正所谓资本制度是资本人格化阶级主导一样,现在的人民也不是现成可用的概念,是要经过社会革命才成立的概念。 2019-06-08
  • Solutions Solutions
    最新新闻 / News More
    1
    2018 - 10 - 10
    AfricaCom is the biggest, best and most influential Tech & Telecoms event on the continent of Africa. It’s a place to meet everybody who’s anybody in African telecoms and technology, AfricaCom brings together 14,000 attendees, 450 speakers and 400 exhibitors. XDK will be exhibiting for the second time.   Whether your focus is connectivity, Infrastructure, disruptive technologies, digital series or ICT strategy, this is the place to network, learn and get deals done with us. We bring high density connectivity products to your business at the heart of African Tech &a...
    联系我们
    移动云网站
    销售热线:0755-2729 6565
    公司总机:0755-2775 9293
    图文传真:0755-2788 8009
    总部地址:深圳市宝安区航城大道西乡光电研发大厦二楼

    WDM Solution

    release date: 2014-07-01
    Browse popular: 333

    天津快乐10分走势图一定牛 www.unxkf.tw WDM Solution


    ? ? The emergence of DWDM is one of the most recent and important phenomena in the development of fiber optic transmission technology. This tutorial will introduce the fundamentals of DWDM technology, such as the components, optical amplifiers used in DWDM system, etc.


    Components and Operation

    ? ??DWDM is a core technology in an optical transport network. The essential components of DWDM can be classified by their place in the system. On the transmit side, there are lasers with precise, and stable wavelengths. On the link, there is optical fiber that exhibits low loss and transmission performance in the relevant wavelength spectra, in addition to flat-gain optical amplifiers to boost the signal on longer spans. On the receive side, there are photodetectors and demultiplexers using thin film filters or diffractive elements. Besides these components, optical add/drop multiplexers and optical cross-connect components may be used.

    The main job of optical fibers is to guide lightwaves with a minimum of attenuation (loss of signal). Multimode fiber and single-mode fiber are the general two categories of optical fiber in use today. Single-mode fiber has a much smaller core that allows only one mode of light at a time through the core. As a result, the fidelity of the signal is better retained over longer distances, and modal dispersion is greatly reduced. These factors attribute to a higher bandwidth capacity than multimode fibers are capable of. For its large information-carrying capacity and low intrinsic loss, single-mode fibers are preferred for longer distance and higher bandwidth applications, including DWDM.

    WDM Solution

    Erbium Doped Fiber Amplifier (EDFA)

    ? ??By making it possible to carry the large loads that DWDM is capable of transmitting over long distances, the?EDFA?was a key enabling technology. Erbium is a rare-earth element that, when excited, emits light around 1.54 micrometers—the low-loss wavelength for optical fibers used in DWDM. The picture below shows a simplified diagram of an EDFA. A weak signal enters the erbium-doped fiber, into which light at 980 nm or 1480 nm is injected using a pump laser. This injected light stimulates the erbium atoms to release their stored energy as additional 1550-nm light. As this process continues down the fiber, the signal grows stronger.

    ?WDM Solution

    Multiplexers and Demultiplexers

    ? ??As DWDM systems send signals from several sources over a single fiber, they must include some means to combine the incoming signals. This is done with a multiplexer, which takes optical wavelengths from multiple fibers and converges them into one beam. At the receiving end, the system must be able to separate out the components of the light so that they can be discreetly detected. Demultiplexers perform this function by separating the received beam into its wavelength components and coupling them to individual fibers. Demultiplexing must be done before the light is detected, because photodetectors are inherently broadband devices that cannot selectively detect a single wavelength.

    In a unidirectional system, there is a multiplexer at the sending end and a demultiplexer at the receiving end shown in the following picture. Two system would be required at each end for bidirectional communication, and two separate fibers would be needed.

    ?WDM Solution

    ? ??In a bidirectional system, there is a?multiplexer/demultiplexer?at each end and communication is over a single fiber pair.

    ?WDM Solution

    ? ??Multiplexers and demultiplexers can be either passive or active in design. Passive designs are based on prisms, diffraction gratings, or filters, while active designs combine passive devices with tunable filters.


    Optical Add/Drop Multiplexers (OADM)

    ? ??Between multiplexing and demultiplexing points in a DWDM system, there is an area in which multiple wavelengths exist. It is often desirable to be able to remove or insert one or more wavelengths at some point along this span. An optical add/drop multiplexer performs this function. Rather than combining or separating all wavelengths, the?OADM?can remove some while passing others on. OADM is a key part of moving toward the goal of all-optical networks.

    ?WDM Solution

    ? ??There are two general types of OADMs. The first generation is a fixed device that is physically configured to drop specific predetermined wavelengths while adding others. The second generation is reconfigurable and capable of dynamically selecting which wavelengths are added and dropped.


    Operation of a Transponder Based DWDM System

    ? ??Within the DWDM system, a transponder converts the client optical signal. The following picture shows the end-to-end operation of a unidirectional DWDM system.

    ?WDM Solution

    The following steps describe the system shown in the picture above.

    1. The transponder accepts input in the form of standard single-mode or multimode laser. The input can come from different physical media and different protocols and traffic types.

    2. The wavelength of each input signal is mapped to a DWDM wavelength.

    3. DWDM wavelengths from the transponder are multiplexed into a single optical signal and launched into the fiber. The system might also include the ability to accept direct optical signals to the multiplexer; such signals could come, for example, from a satellite node.

    4. A post-amplifier boosts the strength of the optical signal as it leaves the system (optional).

    5. Optical amplifiers are used along the fiber span as needed (optional).

    6. A pre-amplifier boosts the signal before it enters the end system (optional).

    7. The incoming signal is demultiplexed into individual DWDM lambdas (or wavelengths).

    8. The individual DWDM lambdas are mapped to the required output type (for example, OC-48 single-mode fiber) and sent out through the transponder.


    Click to view the product


    上一篇:没有上一篇了下一篇:没有下一篇了
    推荐新闻
    X
    等待加载动态数据...

    等待加载动态数据...

    等待加载动态数据...

    等待加载动态数据...

    等待加载动态数据...

    等待加载动态数据...

    等待加载动态数据...

    等待加载动态数据...

    等待加载动态数据...

    等待加载动态数据...

    等待加载动态数据...

    等待加载动态数据...

    等待加载动态数据...

    等待加载动态数据...

    展开
  • 中央环保督察“回头看” 发现两起虚假整改案例 2019-06-25
  • 太平财险湖北分公司成功续保东风乘用车财产险项目 2019-06-25
  • 壮观!150余位画师共绘梵高《星月夜》 2019-06-22
  • 蔡榆的专栏作者中国国家地理网 2019-06-22
  • 弘扬红船精神 当好勇立潮头城建排头兵 2019-06-22
  • 中央和国家机关“建功新时代 岗位作贡献”br劳模精神宣讲报告会在京举行 2019-06-18
  • 最高人民法院再审顾雏军案 2019-06-16
  • 窃贼落网瞒余罪 出狱当天又被抓 2019-06-15
  • 烟 雾谈资中国国家地理网 2019-06-15
  • 新西兰宣布对外国游客征税 称让游客作贡献“非常公平” 2019-06-11
  • 规范二手交易平台须多方给力 2019-06-10
  • 看见什么有用?[猜想] 2019-06-10
  • 女性之声——全国妇联 2019-06-09
  • 王小东周红波现场检查服务“两会”工作 2019-06-09
  • 而其实,正所谓资本制度是资本人格化阶级主导一样,现在的人民也不是现成可用的概念,是要经过社会革命才成立的概念。 2019-06-08
  • 罗马不是一天建成的 巴黎圣日耳曼队 20选5开奖结果11156 炸弹追击注册 八马赛珍珠 安徽快3走势图今天快3 皇家马德里标志 天津时时彩重复开奖 魔术兔电子游戏 拜仁慕尼黑logo