WDM+EDFA+DCF光纤传输系统中色散补偿方案的分析

由于在ＷＤＭ＋ＥＤＦＡ光纤传输系统中使用常规单模光纤（ＳＭＦ）在１５５０ｎｍ窗口的大色散限制了传输距离,采用色散补偿光纤（ＤＣＦ）进行色散补偿是上前一种较为理想的方法。本文基于光纤ＷＤＭ＋ＥＤＦＡ＋ＤＣＦ的长距离传输系统,讨论了ＤＣＦ色散补偿对光纤非线性效应交叉相位调制和四波混频（ＦＷＭ）的影响,提出了采用ＤＣＦ集总、后置、非完全补偿的色散补偿方案,这种方案可合系统具有更佳的传输性能。     

一种闭环控制的光纤光栅动态色散补偿仪

利用啁啾光纤光栅的应变调谐特性，将色散补偿的啁啾光纤光栅斜贴于悬臂梁的侧面，通过应力实现啁啾量调整而改变其色散补偿量的大小，同时利用固定在同一悬臂梁的均匀布拉格光栅传感器，实现了闭环自动控制色散补偿量，研制出了一种新型的光纤光栅动态色散补偿仪。该色散补偿仪工作在1550nm波段，典型性能数据为：色散动态补偿范围-1000-1680ps／nm，插入损耗小于1．5dB，动态调谐步进响应时间小于50ms，基本上能满足10Gb／s光纤通信系统中色散动态补偿的要求。     

色散对有线电视光纤传输的影响

介绍光纤的色散特性,色散对有线电视光纤传输的影响,长距离1 550 nm模拟光传输系统的设计要求,以及现有的色散补偿技术。     

色散对有线电视光纤传输的影响

介绍光纤的色散特性，色散对有线电视光纤传输的影响，长距离1550nm模拟光传输系统的设计要求，以及现有的色散补偿技术。     

Fiber Bragg grating fabrication for dispersion slope compensation

Group-delay dispersion slope causes signal deterioration in long-distance high-data-rate communication systems. We report the fabrication of high-quality apodized and chirped fiber gratings with dispersion slopes as high as -1800 ps/nm/sup -2/ over a 0.7-mn bandwidth-sufficient to compensate for the dispersion slope of >25000-km length of standard fiber at a wavelength of 1550 nm. We believe this is the first time that fiber Bragg gratings have been specifically designed and fabricated for dispersion slope compensation. The fabrication technique uses a standard unchirped phase mask and two scans of the inscribing UV beam.     

10 Gb/s 120-km Bidirectional Repeaterless Transmission over Single-Mode Fiber

A successful repeaterless 10 Gb/s bidirectional transmission experiment is demonstrated at the 1550 nm wavelength through 120 km of single-mode fiber. Fiber chromatic dispersion compensation in both transmission directions is realized by insertion of the same dispersion compensating fiber in the transmission fiber span. Excellent long-term error rate performance (BER < 10-¹⁴) is achieved by suppression of the Rayleigh backscattered signal power with low loss narrow-band fiber grating reflection filters.     

基于光子晶体光纤的宽带色散补偿光纤的设计

采用矢量光束传输法(VBPM)对小纤芯光子晶体光纤(PCF)的色散特性进行了数值分析,研究发现通过调节光子晶体光纤的结构参数可以灵活的对其色散补偿值进行调整,能够实现C L波段(1 530～1 565 nm)的宽带色散补偿功能,并且对标准单模光纤的色散斜率有很好的补偿.在∧=1.0μm,d/∧=0.7时,1 550 nm处的色散值可以达到-339.1 ps/(km×nm),相关色散斜率(RDS)可以达到0.003 2 nm-1,能够有效的对标准单模光纤进行色散斜率补偿.     

啁啾光脉冲在高阶色散控制光纤链中的稳定传输

基于一种二阶和三阶色散补偿的光纤级联系统模型 ,用数值法对啁啾皮秒光脉冲作了传输模拟。结果表明 ,完全补偿的高阶色散控制系统消除了三阶色散所引起的脉冲边沿部的振荡 ,减弱了脉冲峰的时间移动 ;另外 ,在确定的配置下 ,给输入脉冲附加一最佳的频率啁啾 ,可使得色散控制孤子稳定传输。脉冲宽度和啁啾以及光强度都围绕在初始值附近波动 ,在每个补偿周期末端 ,基本恢复到初始值 ;最佳啁啾的选取与二阶色散的配置有关 ,与三阶色散的配置无关 ;文中画出了 10 0Gbit/s码率的 64位随机高斯光脉冲序列在完全补偿系统中传输 10 0 0 0km后的眼图。由清晰的眼图可知 ,这种完全补偿系统减弱了脉冲之间的相互作用     

区县1550nm灾备传输系统设计和测试

为确保广播电视信号不间断传输,增强对突发事件的应急响应能力,杭州利用1 550 nm传输技术结合色散补偿技术,建设了区县数字电视灾备信号模数混合传输网。介绍杭州区县1 550 nm灾备传输网设计方案和系统指标测试,证实1 550 nm经过300多km传输后仍然具有优良的播出质量,满足国家广电总局新颁布的《广播电视安全播出管理规定》的要求,1 550 nm光纤传输技术在数字电视区县联网中具有广阔的应用前景。     

1310nm和1550nm波长的光纤弯曲损耗及对光缆线路测试的探讨

单模通信光纤在1550nm波长的损耗小于在1310nm波长的损耗,而在1550nm波长光纤的弯曲损耗大于在1310nm波长光纤的弯曲损耗。基于这种事实,文章对光缆线路工程中简化光纤测试工作的方法和意义以及有关弯曲损耗的一些值得注意的实际问题进行了详细的讨论。     

一种基于波分复用技术的频率传输远端补偿新方案

为解决光纤频率传输系统大规模组网带来的中心设备复杂、工作负荷大和可靠性低等问题,提出了一种相位波动在远端自主补偿的频率传输新方法.该方法采用波分复用技术,将信号通过双支路传输至远端,通过鉴相、相关计算实现相位波动的高精度测量,通过电学移相实现高精度补偿.理论仿真验证了该方法的有效性.在传输频率为10 MHz、通信窗口分别为1310和1550 nm、光纤链路长度为25 km的仿真测试中,远端信号的同步精度达到0.22 mrad.     

Negative dispersion-flattened fibre suitable for 10 Gbit/s directly-modulated signal transmission in whole telecommunication band

New dispersion-flattened fibres having negative dispersion of about -8 ps/nm/km over the whole telecommunication band are developed. Transmissions with 10 Gbit/s directly modulated LDs over 51 km at 1275 nm and over 80 km at 1550 nm are realised without dispersion compensation.     

新型低成本色散测试仪的研制

介绍了一种新型的基于普通单模光纤的低成本色散测试仪的研制方法,主要讨论了设计原理,硬件电路的实现及实验结果。通过引入波长为1310nm的参考光,不仅以波长间隔大的1310/1550nmWDM(波分复用/解复用器)代替了波长间隔小的1550nm附近的WDM,而且巧妙地消除了系统随机误差,并在软件部分采用自动校准、多次测量求平均值的方法,保证了测量的精度,具有较高的稳定性和抗干扰能力。     

25-Gb/s optical NRZ transmission over 40 km of single-mode fiber at 1550 nm without dispersion compensation

We present a method for transmitting 25-Gb/s optical nonreturn-to-zero signals at a wavelength of 1550 nm over a 40-km single-mode fiber without any dispersion compensation methods. We propose optimized self-phase modulation by varying parameters of the fiber launching power and the extinction ratio of optical non-return to zero signals to overcome severe signal distortions by the chromatic dispersion effect. Using the optimization of the self-phase modulation effect, we were able to transmit 25-Gb/s optical nonreturn-to-zero signals over a 40-km single-mode fiber, which can be applicable to passive optical networks with a single wavelength channel and a high split ratio. We demonstrated that the self-phase modulation effect can be controlled by the extinction ratio and the fiber launching power.     

48 fs,108 MHz色散管理孤子掺Er3+光纤激光器

提出了一种基于商售光纤构建的适用于精密光谱光频梳应用的100 MHz重复频率色散管理孤子光纤激光器的设计方案.通过采用低负色散光纤调控重复频率、高正色散光纤增大腔内脉冲呼吸比,构建了重复频率为108 MHz、中心波长为1550 nm的基于正色散掺铒光纤的色散管理孤子光纤激光器,该激光器腔内净色散为-0.0023 ps2,直接输出脉冲宽度为70 fs,经光纤压缩后脉冲宽度为48 fs,且脉冲中心波长处在1550 nm.     

Broadband multiwavelength simultaneous dispersion compensation near 1550 nm through singlemode fibres optimised for 1310 nm

Broadband dispersion compensation is demonstrated at 2.5 and 10 Gbit/s using an optical-fibre equaliser in combination with pulse compression. At 2.5 Gbit/s, simultaneous penalty-free dispersion compensation is achieved in a four-wavelength system operating at 1550 nm through 67 km of 1310 nm-optimised singlemode fibre. Low penalties are obtained over the full 20 nm gain bandwidth of the erbium-doped fibre amplifier, with the receiver sensitivity slightly enhanced at the short-wavelength end.<>     

Compensation for fiber-induced composite second-order distortion inexternally modulated lightwave AM-SCM systems using optical-phaseconjugation

Compensation for composite second-order (CSO) distortion due to the interplay of fiber chromatic dispersion and self-phase modulation in externally modulated amplitude modulated subcarrier multiplexing (AM-SCM) systems employing optical-phase conjugation (OPC) is investigated. The simulation results show that significant reductions (>20 dB) of fiber-induced CSO may be achieved using OPC, which results in an increase of the transmission distance in AM-SCM video distribution systems operating near 1550 nm. In addition, a comparison with another compensation technique, the phase modulation technique, is established, showing that OPC is much less sensitive to variations in the fiber length. However it is also calculated that for practical implementation of the OPC-based compensation technique, 25 to 30 dB reduction in the amplified spontaneous emission (ASE) associated with the OPC will be required     

一种新型高双折射光子晶体光纤的特性研究

设计了一种新型结构的光子晶体光纤,建立了对应的数学模型并采用全矢量有限元法对该结构的模场强度、有效折射率、双折射、色散特性和限制损耗进行了分析。研究表明,该光纤在1 550nm处可以获得高达7.66×10-3的双折射和低至12ps/(nm·km)的色散值,同时在800～1 600nm波长范围内,始终保持1.498×10-6 dB/m以下的极低限制损耗,可用于制造极低色散值的保偏光纤。     

Experimental evaluation of chromatic dispersion distortion inoptical CPFSK transmission systems

Receiver sensitivity degradations due to fiber chromatic dispersion without chromatic dispersion compensation in multigigabit optical continuous-phase frequency-shift-keying (CPFSK) transmission systems are evaluated experimentally and theoretically. Transmission distance limited by the chromatic dispersion of 15 ps/nm/km is estimated to be 130 km at 5 Gb/s and 33 km at 10 Gb/s     

基于射频信号2阶零功率的链路色散测量技术

为了适应高速率大色散光纤信道对链路色散的精确补偿要求,研究并提出了一种基于射频信号2阶零功率点的信道色散测量方案。采用信号两边带的位相差来测量光纤链路中的色散值,通过在发射端加载射频信号,可以得到接收端射频信号功率大小随链路色散值的周期性变化关系,从仿真光纤链路色散随射频信号频率的变化曲线获得接收端射频信号2阶零功率点位置。结果表明,基于射频信号2阶零功率的信号测量方案色散测量误差可控制在±10ps/nm范围内。相较于1阶零功率点,基于射频信号2阶零功率点信道色散测量方案可满足高速率、长距离大色散光纤信道对色散值的精确测量需求。