共查询到18条相似文献,搜索用时 140 毫秒
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动态光网络中交叉相位调制和放大自发辐射噪声积累效应的传输代价 总被引:1,自引:1,他引:0
研究了动态密集波分复用(DWDM)光网络中直接调制-强度检测(IM-DD)系统中的交叉相位调制(XPM)和放大自发辐射(ASE)导致的动态噪声积累效应对高速光脉冲传输时的强度噪声影响,修正目前IM-DD系统中传输代价Q参数的计算公式.通过仿真分析了动态网络环境下两种噪声积累对动态光路径接收端误码率(BER)的影响,得出了XPM相位噪声与动态网络中光纤段长度、段数、波长信道间隔、链路ASE噪声等在内的链路参数之问的关系.对于动态光网络中链路的选择具有很好的参考价值. 相似文献
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交叉相位调制对密集波分复用系统性能的影响 总被引:1,自引:0,他引:1
研究了交叉相位调制对密集波分复用系统性能的影响 ,分析了干扰信道为正弦调制时交叉相位调制效应对考察信道相位的影响 ,在此基础上 ,建立任意信号通过具有交叉相位调制效应的信道时的系统模型 ,并将该模型应用于基带不归零码数字信号传输的情形 ,计算了由交叉相位调制引起的系统光功率代价。结果表明 ,交叉相位调制效应对高速率调制系统的性能具有一定的影响 ,应该在系统设计时的功率预算中予以考虑。 相似文献
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XPM对WDM系统中一阶PMD补偿的影响 总被引:1,自引:0,他引:1
介绍了交叉相位调制(XPM)效应的概念,数值分析了其对波分复用(WDM)系统中一阶偏振模色散(PMD)补偿性能的影响.文章基于两信道WDM系统PMD效应模型,数值模拟了XPM对一阶PMD补偿性能的影响,对比分析了考虑XPM前后系统的性能.文中给出了采用补偿后考虑XPM以及不考虑XPM时信道的眼图,可以看出XPM在一定程度上降低了眼图的张开度,削弱了一阶PMD补偿效果. 相似文献
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高效多信道波长转换技术对于将来灵活的全光网络应用具有重要的意义。在本文中我们从数值上分析了幅度调制信号,相位调制信号,以及混合幅度调制信号和相位调制信号的多信道波长转换技术。本文同时也讨论了受激布里渊散射效应及其对于基于四波混频效应的高效波长转换技术的影响。分析结果表明差分相位调制信号(DPSK)更加适合基于四波混频效应的多信道波长转换技术,因为多信道OOK波长转换的信号将会受到无法避免的码型相关损耗效应的影响。在将来的应用中,当调制格式由传统的OOK格式部分升级为DPSK格式的时候,在多信道波长转换情况下的OOK信号对于升级的DPSK信号的影响必须要仔细考虑,并且这种影响随着OOK信道数目的增加变得更加严重。因此我们可以得出如下结论,DPSK信号更加适合于传输和多信道波长转换的需要,尤其是在长距离传输和高比特速率的系统中。 相似文献
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推导了多个信道和任意调制的情况下XPM效应对光纤WDM系统性能的影响,通过数值模拟计算表明了在此情况下XPM效应是限制系统性能一个重要因素,应在系统功率预算中给予考虑。提出了抑制XPM影响的几种方法。 相似文献
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This paper develops a vector theory of cross-phase modulation (XPM) in optical fibers and use it to investigate the impact of polarization-mode dispersion (PMD) on the crosstalk induced by XPM in wavelength-division multiplexed lightwave systems. Under certain reasonable approximations, the theory permits us to obtain an analytic expression for the amplitude of probe fluctuations induced by a copropagating pump channel through XPM. We use this expression to calculate the average level of XPM-induced crosstalk together with its variance for several dispersion maps. We show that PMD not only reduces the crosstalk on average, but also impacts the efficiency of a commonly used polarization-interleaving technique. 相似文献
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We investigate, theoretically and experimentally, crosstalk between wavelengths in subcarrier-multiplexed (SCM) wavelength-division multiplexed (WDM) optical communication systems. Crosstalk arises mainly from interactions between subcarriers on one wavelength and the optical carrier of another wavelength. In a dispersive fiber, crosstalk can be attributed to stimulated Raman scattering (SRS) and cross-phase modulation (XPM) combined with group velocity dispersion (GVD). We investigate the phase relationship between SRS-induced and XPM-induced crosstalks. Crosstalks induced by SRS and XPM add in the electrical domain and can interfere constructively or destructively. Experimental results show that the combined crosstalk level can be as high as 40 dBc after 25 km of SMF with two wavelengths and 18 dBm per wavelength of transmitted power. We propose two crosstalk countermeasures. The first countermeasure uses parallel fiber transmission. We show theoretically that both SRS-induced and XPM-induced crosstalks can be cancelled to the first order. We present an experimental demonstration of concept which has achieved 15 dB of crosstalk cancellation over 200 MHz. The second countermeasure uses optical carrier suppression. We show, theoretically and experimentally, that by suppressing the optical carrier, we can significantly reduce crosstalk while maintaining the same link budget and carrier-to-noise ratio (CNR) at the receiver, 20 dB of crosstalk reduction over 2 GHz has been demonstrated experimentally 相似文献
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Cross-phase modulation in multispan WDM optical fiber systems 总被引:4,自引:0,他引:4
The spectral characteristics of cross-phase modulation (XPM) in multispan intensity-modulation direct-detection (IM-DD) optical systems are investigated, both experimentally and theoretically. XPM crosstalk levels and its spectral features are found to be strongly dependent on fiber dispersion and optical signal channel spacing. Interference between XPM-induced crosstalk effects created in different amplified fiber spans is also found to be important to determine the overall frequency response of XPM crosstalk effects. XPM crosstalk between channels with different data rates is evaluated. The crosstalk level between higher and lower bit rate channels is found to be similar to that between two lower bit rate channels. The effect of dispersion compensation on XPM crosstalk in multispan optical systems is discussed and per span dispersion compensation was found to be the most effective way to minimize the effect of XPM crosstalk 相似文献
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《Lightwave Technology, Journal of》2009,27(18):3974-3983
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In this paper, a dynamic optical arbitrary waveform generator (OAWG) based on cross phase modulation (XPM) is proposed. According to the characteristics of XPM, the nonlinear phase shift of signal can be changed along with the pump power. The amplitude of signal can be changed by controlling the phase shift at one arm of a Mach-Zehnder interferometer (MZI) using XPM effect between signal and pump. Therefore, the phase and amplitude of the optical frequency comb (OFC) can be controlled by two pump arrays. As a result, different kinds of waveforms can be synthesized. Due to the ultrafast response of XPM, the generated waveform could be dynamically updated with an ultrafast frequency. The waveform fidelity is affected by the updating frequency. 相似文献
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The spectral characteristics of cross-phase modulation (XPM) in multispan intensity-modulation direct-detection optical systems were investigated both experimentally and theoretically. XPM crosstalk levels and its spectral features were found to be strongly dependent on fiber dispersion and optical signal channel spacing. Interference between XPM-induced crosstalk effects created in different amplified fiber spans is also found to be important to determine the overall frequency response of XPM crosstalk effects 相似文献
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Differential phase shift keying (DPSK) modulation is being considered as a possible candidate for future optical wavelength division multiplexed (WDM) transmission systems. In a single channel link, the balanced interferometric DPSK receiver exhibits increased tolerance against amplified spontaneous emitting (ASE) noise and fiber nonlinear effects. In this paper, a model is presented that can be used to estimate the performance of a multichannel DPSK system taking into account the influence of interchannel phenomena, namely cross-phase modulation (XPM) and four wave mixing (FWM), in the phase noise statistics. The model is based on an approximate solution of the fiber propagation equation and the multicanonical Monte Carlo (MCMC) method. It provides an efficient tool that can be used to investigate the influence of many link design parameters such as channel spacing, launch power, and fiber dispersion. The model is illustrated in the comparison of the performance of multichannel DPSK to on-off keying (OOK) systems. It is verified that, even in the presence of interchannel effects, DPSK modulation greatly enhances the system performance compared to OOK. 相似文献