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1.
GUO Shuqin XIAO Yan XUE Wenrui LI Zhonghao ZHOU Guosheng Department of Physics Shanxi University Taiyuan China Department of Electronics Shanxi University Taiyuam China Received Aug. Re 《Chinese Journal of Lasers》2001,10(4):277
1 Introduction Despitethegreatsuccessofwavelengthdivisionmultiplexed (WDM )systemsinachievinghigh capacitytransmission ,thereremainsinterestinexploringthecapabilitiesofhighdatarateinsinglechannelsystems.Thepropagationofchirpedpulsesinopticalfibersisofgr… 相似文献
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初始啁啾补偿光纤色散效应的适用范围 总被引:6,自引:5,他引:1
以啁啾高斯脉冲在单模光纤中的传输为例,分别就线性初始啁啾对光纤二阶和三阶色散的补偿进行了系统的理论分析和数值计算,结果表明:线性初始啁啾对光纤的二阶色散(线性色散)有一定的补偿作用,但不能有效地用于三阶色散的补偿. 相似文献
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光纤通信系统中基于光学相位共轭和预啁啾的色散及非线性补偿研究 总被引:2,自引:0,他引:2
采用光学相位共轭补偿光纤通信系统的色散及非线性必须满足一个前提条件,即相位共轭器两边线路上的色散和非线性分布(或传输功率分布)必须严格对称,这在现有的一般传输线路(标准单模光纤加集总掺铒光纤放大器)难以实现。提出了预啁啾结合中距相位共轭的补偿方案,并进行了数值计算。结果表明,通过在发送端对输入脉冲进行预啁啾展宽,可有效地减轻非线性效应与色散的相互作用,获得理想的补偿效果;对于皮秒超短光脉冲传输,脉冲内拉曼散射相对于三阶色散对补偿结果的影响很小,因此,频域相位共轭相对于时域相位共轭具有更好的综合补偿性能。该方案简单易行,无需对已敷设好的线路作较大改动。 相似文献
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In this article we present improved theoretical investigations into relative intensity noise (RIN), including the impact of a third-order dispersion term for dispervive optical communication systems. It has been shown that the third-order dispersion term has no impact on RIN even at high noise frequencies as reported by other authors, but with second-order dispersion compensation, the RIN can be dramatically reduced, thereby improving overall system performance. Further, the impact of fiber length and laser linewidth has been investigated for RIN. It has been shown that, as the fiber length increases, the value of RIN increases but the improvement over RIN with second-order dispersion compensation decreases. Also, with decrease in the value of linewidth, the RIN can be reduced to a great extent. 相似文献
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双光栅快速扫描光学延迟线的色散补偿 总被引:1,自引:0,他引:1
光学相干层析成像(OCT)系统的纵向分辨力不仅与光源的带宽有关,而且与系统中两干涉臂间的色散匹配有关。如果色散没有得到精确匹配,将使光学相干层析成像系统的纵向分辨力达不到所预期的理论值。色散问题在超高分辨光学相干层析成像系统中尤为突出。提出了一种基于双光栅快速扫描光学延迟线(RSOD),用于光学相干层析成像系统的色散补偿。该方法中新增的光栅引入了光栅间距这一独立变量,其与常规单光栅快速扫描光学延迟线机构中的光栅离焦量一起,可使光学相干层析成像系统中的群速度色散(GVD)和三阶色散(TOD)同时得到补偿。分析了双光栅快速扫描光学延迟线的色散特性和色散调节原则,并提供了一个典型光学相干层析成像系统中的色散补偿实例。 相似文献
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Zhenhong Sun Lu Chai Zhigang Zhang Chingyue Wang Weili Zhang Xudong Xie Xiaojun Huang Xiaodong Yuan 《Optics & Laser Technology》2007,39(1):29-33
In this paper, based on ray tracing, the approach of mutual compensation that introduced properly the negative third-order dispersion to balance the higher-order dispersion in the chirped pulse amplification (CPA) system with regenerative amplifier is presented. A shorter pulse with near-transform-limitation can be generated by this method than by the conventional approach that zeros the second- and the third-order dispersion successively in the CPA system. 相似文献
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We present results for duty cycle selection of optical RZ pulse to optimize the performance in 10 Gbps single channel dispersion compensated optical communication system. The system has link length of 240 km with two spans. Each of the spans consists of 120 km standard single mode fiber (SSMF) of 16 ps/nm/km, whose chromatic dispersion is compensated using pre-, post- and symmetrical-dispersion compensation schemes by 24 km dispersion compensating fiber (DCF) of −80 ps/nm/km. The performance of the three compensation schemes is compared by taking 8, 10, 12 and 14 dBm Er-doped fiber amplifier (EDFA) power levels in the link with a duty cycle range (0.1-0.9) of RZ optical pulse. The graphical results obtained show a relationship among the duty cycle, EDFA power and dispersion compensation scheme which predicts the best performing duty cycle case. To optimize performance of the system, we recommend in general, duty cycle less than 0.3 and EDFA power below 8 dB irrespective of compensation scheme. However, with post compensation duty cycle less than 0.7 and EDFA power below 12 dBm give optimum performance. The results conclude that for the high value of duty cycle, post dispersion compensation scheme should be used. 相似文献
9.
Improving performance of optical fibre chaotic communication by dispersion compensation techniques 下载免费PDF全文
This paper numerically investigates the effects of dispersion on optical fibre chaotic communication, and proposes a dispersion compensation scheme to improve the performance of optical fibre chaotic communication system. The obtained results show that the transmitter-receiver synchronization progressively degrades and the signal-to-noise ratio of the recovered message deteriorates as the fibre length increases due to the dispersion accumulation. Two segments of 2.5-km dispersion-compensating fibres are symmetrically placed at both ends of a segment of 245-km nonzero dispersionshifted fibre with low dispersion in one compensation period. The numerical results show that the signal-to-noise ratio of the extracted 1 GHz sinusoidal message is improved from -2.92 dB to 15.38 dB by this dispersion compensation for the transmission distance of 500 km. 相似文献
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We show the effect of varied order and width of super Gaussian pulse at 10 Gb/s in dispersion compensated optical communication system. The optical communication system consists of standard single-mode fiber of 16 ps/nm/km of a certain length, whose dispersion is compensated using pre-, post- and symmetrical-dispersion compensation schemes with proportionate length dispersion compensating fiber of −80 ps/nm/km. Performance of these three compensation schemes is compared at 14 dBm values of Er-doped fiber amplifiers (EDFA) power at 1st, 2nd and 3rd order RZ super Gaussian optical pulse. The pulse width, full width at half maximum (FWHM) is also varied from 5 to 30 ps to highlight the optimum performance. The graphical results obtained show a relationship among the attributes pulse width, order of RZ super Gaussian optical pulse and dispersion compensation scheme implemented. It shows that to decrease BER and timing jitter in the system, smaller width and 3rd order super Gaussian pulse should be used. It is recommended that to decrease dependency of BER and timing jitter in the communication system on the pulse width i.e. FWHM, the symmetrical compensation scheme should be implemented. 相似文献
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The impact of third-order dispersion (TOD) is investigated by numerical simulations in 160-Gb/s singlechannel systems incorporated with dispersion mapping and optical phase conjugation (OPC). System performances using retrun-to-zero (RZ) or carrier-suppressed RZ (CSRZ) modulation format are evaluated on the optimized dispersion map. The results indicate that even though TOD has been fully compensated,the intra-channel nonlinearity induced by local TOD would degrade the system performance in nonlinear regime. The scheme with an optimized dispersion map provides a much higher performance and offers a larger tolerance on a variation of pre-compensation. CSRZ modulation format is more robust due to its tradeoff between tolerances on intra-channel nonlinearity and dispersion. 相似文献
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Dispersion accumulation with the distance effects optical WDM system's performance severely. For every modulation format used there is a limit on maximum transmission distance due to dispersion accumulation. So dispersion compensation is required. But dispersion compensation can be avoided to a large extent by alternatively using different fiber standards. In this paper it has been proposed that the dispersion accumulation can be reduced to a large extent by alternatively transmitting in S-band and using fiber standards ITUT-652a and ITUT-655. To validate the claim, performance of a 16 channel 10 Gbps WDM system with the proposed method has been analyzed in terms of BER and Q-factor. And it has been observed that with the proposed scheme without any dispersion compensation the system performs well up to 1400 km. 相似文献
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《中国光学快报(英文版)》2017,(3)
The common and traditional method for optical dispersion compensation is concatenating the transmitting optical fiber by a compensating optical fiber having a high-negative dispersion coefficient.In this Letter,we take the opposite direction and show how an optical fiber with a high-positive dispersion coefficient is used for dispersion compensation.Our optical dispersion compensating structure is the optical implementation of an iterative algorithm in signal processing.The proposed dispersion compensating system is constructed by cascading a number of compensating sub-systems,and its compensation capability is improved by increasing the number of embedded sub-systems.We also show that the compensation capability is a trade-off between the transmission length and bandwidth.We use the simulation results to validate the performance of the introduced dispersion compensating module.Photonic crystal fibers with high-positive dispersion coefficients can be used for constructing the proposed optical dispersion compensating module. 相似文献
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<正>A novel structure for ultra long span optical transmission systems is proposed.In the scheme,the inverse fast Fourier trans form(IFFT) is used as a way of inverse multiplexing.A 40-Gb/s(total effective capacity) system based on the proposed scheme is simulated to evaluate its performance without consideration for dispersion compensation.Simulation results indicate that the proposed system can tolerate distortion caused by chromatic dispersion effectively after long distance transmission. 相似文献
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Yong Wang Weili Zhang Jianming Dai Lizhe Zhang Lu Chai Qirong Xing Ching-yue Wang 《Optics & Laser Technology》2000,32(2)
Numerical results for the second- and third-order dispersion in PW prism-sequence (double prism-pair) with arbitrary apex-angle by ray-tracing method are presented. The influence of the prism separation distance and apex-angle on second- and third-order dispersion is discussed. In certain conditions, the PW prism-sequence with small apex-angle (20°) is a better choice to reduce third-order dispersion than single prism-pair without requiring excessive length. As a less dispersion material, quartz is suitable to be used with the smallest possible value of third-order dispersion. This result could be the basis of dispersion compensation and pulse compression. 相似文献
17.
本文建立了偏分复用系统中偏振模色散与信号偏振态变化引起信道串扰的数学模型, 分析了偏振模色散对偏分复用信道射频功率的影响, 并提出了适用于偏分复用系统的光域偏振模色散补偿与偏分解复用同时进行的方案: 用信道的射频功率作为反馈控制信号, 监测链路中偏振模色散和偏振态变化引起的信道串扰的大小, 用改进的粒子群优化算法对偏振控制器进行自适应控制, 同时完成偏振模色散补偿与偏分解复用. 在112 Gb/s偏分复用-差分正交相移键控(PDM-DQPSK)传输系统中仿真验证了该方案的有效性. 结果表明该方案可以使112 Gb/s-PDM-DQPSK传输系统完成自适应偏分解复用的同时, 在1 dB的光信噪比代价下, 使系统对偏振模色散的容忍度提高20 ps.
关键词:
偏分复用系统
信道串扰
偏振模色散
偏分解复用 相似文献
18.
Parabolic pulse propagation in a dispersion-decreasing fiber with normal group velocity dispersion (ND-DDF) has been studied
when the third-order dispersion (TOD) is included. The results show that the characteristic of exact self-similarity and linear
chirp will be lost due to the third-order dispersion. However, by using the dispersion compensation technique, one can obtain
efficient and high-quality compressed pulses. The analytic results have been confirmed using numerical simulations. 相似文献
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为了保证移动地面站光电跟瞄系统在野外复杂环境下具有稳定的跟踪精度,针对-20~40℃宽工作温度范围下信标接收镜头成像光斑弥散的问题,进行了光学系统与光机结构的设计,提出了一种以步进电机驱动补偿镜组的温度补偿方案。分析了极限温度条件下光学系统性能的改变以及不同温度补偿方案的效果,针对光电跟瞄系统的指标要求,设计了光机结构并进行了力学、光学性能的分析。分析结果表明,系统一阶模态为370 Hz;补偿镜组向前移动0.695 mm能够补偿-20℃时光学系统成像光斑的弥散,令中心视场光斑尺寸由73μm降为3.2μm,边缘视场光斑尺寸由77μm降为15.7μm;向后移动0.885 6 mm能够补偿40℃时成像光斑的弥散,令中心视场光斑尺寸由94μm降为3.9μm,边缘视场光斑尺寸由96μm降为21.8μm;使用ZYGO干涉仪对光学系统的像质进行检测,波像差RMS值(均方根值)为0.061λ(λ=632.8 nm),PV值(峰谷值)为0.466λ,能够满足跟瞄系统指标要求。 相似文献