共查询到19条相似文献,搜索用时 156 毫秒
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光纤中具有轻微的非线性和一定的色散特性,这两种特性分开来说,将会损害光纤通信中系统的性能,但是在一定的条件下,这种小的非线性的影响可以抵消色散的影响,产生孤子.在无耗的光纤介质中,孤子可以传输任意距离而不改变形状.实际的有耗光纤中,为了使用孤子,用光放大器来抵消光纤的损耗,以维持链路上孤子能量的稳定.通常在光纤中非线性和色散效应都比较弱,对光纤的作用表现为两种效应的相加性.放大器的自发辐射噪声(ASE),通过两种不同的机理增加了系统的误码率(BER):(1)通常的加性噪声的影响;(2)孤子速度的抖动.第二种效应导致脉冲到达时间的抖动,这就是Gordon-Haus效应.由于光纤存在损耗,光孤子在光纤里的传输过程中,其幅度随传输距离按指数规律衰减,必须对孤子能量进行放大.一种是分布式光放大器方法;另一种是集总式光放大器方法.分布式EDFA使用低浓度的掺铒光纤作为传输介质.集总式放大就是在光纤线路中每隔一段距离L接入一段集总式光纤放大器(目前通常采用EDFA)来补偿孤子能量的损失.本文研究了孤子传输在存在损耗和放大器自发辐射噪声(ASE)时的孤子传输方程及其解.并对孤子传输的控制作了概述.(PD3) 相似文献
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数值模拟了强度调制光信号在级联光纤放大器普通单模光纤通信系统中的传输,模拟中主要考虑了自相位调制、群速色散和自发辐射噪声,使用负色散补偿光纤去补偿群速色散和自相位调制。结果表明,若色散得到很好补偿,当放大器间距减少到50km时,无误码2050km传输是可能的。 相似文献
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色散管理和非线性管理控制光孤子群的传输 总被引:1,自引:1,他引:0
从描述光孤子传输的非线性薛定谔(NLS)方程出发,给出了色散管理和非线性管理的光孤子的传输方程,利用对称分步傅里叶方法对方程进行数值求解,模拟研究了色散管理和非线性管理控制光孤子在光纤中的传输演化特性。结果表明,只有色散管理控制光孤子群在光纤中的传输,随着传输距离增加,孤子间的相互作用逐渐加剧,如色散管理和非线性管理同时控制光孤子群在光纤中的传输,可极大地抑制孤子间的相互作用,且随着距离增加相邻孤子间的作用几乎不变,这一结果可应用于光孤子群远距离的传输。 相似文献
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利用光子晶体光纤实现10 Gb/s光传输系统的色散补偿 总被引:8,自引:2,他引:6
利用光子晶体光纤(PCF)在10Gb/s光传输系统中对普通单模光纤中传输的光脉冲进行了色散补偿,获得了很好的补偿效果。实验中,10Gb/s光脉冲序列经过2.163km普通单模光纤被展宽后.利用26m长光子晶体光纤对其进行色散补偿.补偿后脉冲基本恢复到了初始形状。进一步的理论计算表明,此光纤在C波段20nm波长范围内对普通单模光纤能够实现较好的色散斜率补偿,补偿后剩余色散小于5ps/nm。理论与实验结果表明光子晶体光纤在色散补偿方面具有很大的潜力.在未来光通信系统中将发挥重要作用。 相似文献
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通过计算机系统仿真研究了应用相敏光放大器(PSA)作为在线放大器的光孤子传输系统,并与相应的掺铒光纤放大器(EDFA)光孤子系统作了比较。仿真了平均孤子和动态孤子两种传输方案.研究结果表明,由于PSA不存在ASE噪声,应用PSA作为在线放大器可以克服光孤子系统中的Gordon-Haus限制.对平均孤子,在没有附加其它的孤子控制技术的情况下,PSA系统孤子的稳定传输距离得到极大的延长.对动态孤子,PSA亦表现出良好的抑制脉冲展宽效果,但脉冲的幅度经长距离传输后显著下降. 相似文献
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光子晶体的反常色散特性为色散补偿、短波长光孤子传输和超短脉冲压缩提供了可能,而普通单模光纤的零色散点总向长波方向移动,为此,文章研究了通过合理的设计光子晶体光纤来使TIR-PCF零色散点向短波推进,以在几百nm范围内取得零色散的方法。 相似文献
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采用变分法讨论了放大器噪声对色散管理光孤子脉冲参数的影响。讨论了ASE噪声对脉冲相位、脉冲中心时间和中心频率的影响,并且对比讨论了采用密集色散管理系统和降低平均色散值后,ASE噪声对脉冲的影响,结果表明:密集色散管理孤子系统和平均色散接近于零的色散管理系统更有利于降低放大器噪声对脉冲的扰动。 相似文献
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人们熟知,由非线性薛定谔(NLS)方程描述的光学孤子可以在单模光纤中稳定地传输。本文在准单色近似和慢变包络近似条件下,利拥泰勒级数展开推出了这一非线性传输方程。由于推出的方程包含着高阶线性色散和光纤损耗项,因而可以用来研究短光脉冲(皮秒量级)在单模光纤传输过程中相关的非线性光学孤子效应,比如光学孤子分裂和光学孤子损耗等。 相似文献
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光孤子通信技术充分利用了光纤中色散参数和非线性效应的相互作用,可以使光脉冲在光纤中无畸变的进行传输,不受外界条件的影响,从而可以实现脉冲的超长距离传输。利用OptiSystem提供的强大的工具箱,模拟了光孤子通信系统的模型。并在给定的参数下,实现了系统的仿真,证实了仿真模型的可行性和正确性,为将来在此基础上实现改进的光孤子通信系统提供了有力的实验依据。 相似文献
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In this paper, we show a comparison among the performance of single- and multichannel optical systems considering NRZ and soliton signals. The results have been obtained by means of numerical simulations, taking into consideration the chromatic dispersion, the Kerr nonlinearity, the fiber loss, and the ASE noise of the optical amplifiers. The performance of IM-DD and coherent asynchronous ASK systems have been evaluated in terms of the Q factor. We have considered the propagation in links encompassing conventional step-index fibers, DS fibers and in links with two different dispersion management techniques in which the chromatic dispersion is varied along the propagation distance both in randomly and in deterministically way. The effects of the in-line filtering process are mainly investigated in soliton propagation 相似文献
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In anormalous dispersion of monomode optical fiber,optical solitons are evolvedfrom optical pulses when the dispersion is balanced by the nonlinearity.Undistorted transmissioncan be realized by using optical solitons,which can offer much greater the transmission capacityand extend the repeater spacing of the fiber communication system.The mechanism of thegeneration of optical solitons is expounded.A few forms of nonlinear transmission equationare obtained by using a concise method.The general complete expression of elementary solitonsolution of the nonlinear transmission equation without loss is given,and the design of the solitontransmission system is discussed. 相似文献
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针对传统C波段高速光模块传输距离过短的问题,文章对一种准相干接收技术进行了研究,结合现有25 Gbit/s光模块进行了实验,并讨论了准相干接收技术的应用方案.研究发现,准相干接收技术以外差相干检测技术为基础,具有结构简单和成本低等优点,在不使用额外的电或光色散补偿技术的前提下,准相干接收机也能有效减少色散对高速光模块传... 相似文献
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Carena A. Curri V. Gaudino R. Poggiolini P. Benedetto S. 《Lightwave Technology, Journal of》1998,16(7):1149-1157
Parametric gain (PG) in optical fibers may substantially enhance amplified spontaneous emission (ASE) noise, especially in long-haul amplified links. We present new results that permit to accurately characterize the effects of PG on ASE noise, as well as the interplay of PG and ASE noise with fiber dispersion in both the anomalous and normal dispersion regions. In a recent letter, we introduced the concept of a PG transfer matrix, that allows the easy evaluation of ASE noise enhancement over chains of amplified fiber spans. In the same letter we showed that the transfer matrix can be expressed in analytical closed-form when a scalar (single polarization) fiber is assumed. In this paper we extend the analysis to a more realistic two-polarization fiber model that accounts for both linear and nonlinear polarization coupling effects. We show that the new transfer matrix does not have an analytical expression, but can be easily evaluated using standard numerical algorithms. ASE noise enhancement due to PG turns out to be slightly lower in a realistic birefringent two-polarization fiber than a single-polarization fiber. An interesting result is that the single polarization model yields a convenient approximation to ASE noise enhancement, that can be evaluated analytically 相似文献
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The dynamic behavior of single-channel transmission on standard fibers with strong dispersion management has been theoretically and numerically analyzed. A single pulse and a pseudorandom pulse sequence have been compared in order to highlight the relevant role played by pulse interaction. A semianalytical theory of the bandwidth evolution demonstrates that the introduction of prechirp is very important for controlling the single pulse propagation and numerical results show that such a chirp also permits to limit the nonlinear pulse interaction when other pulses are present. Simulations of a 40 Gb/s return-to-zero (RZ) system operating in links encompassing step-index fibers, by adopting a periodical compensation of the chromatic dispersion have been performed and results show that a record distance of 1300 km can be achieved with an amplifier spacing of 100 km. A compensation of the fiber third order dispersion would extend the transmission to 1800 km, which corresponds to the limits imposed by the amplified spontaneous emission (ASE) noise of the optical amplifiers 相似文献