高速光纤通信系统中交叉相位调制效应研究

【作者】 李中桂；

【导师】 邱昆；

【作者基本信息】 电子科技大学 ， 光学工程， 2003， 硕士

【摘要】 光纤通信系统正在向宽带、大容量的方向发展。密集波分复用技术作为目前干线光纤通信应用的最广泛的方式，也得到了长足的发展。入纤功率的增加和信道间隔的减小都导致了以前通常被忽略的非线性效应凸现出来，并成为光纤通信容量进一步增长的限制。本文主要研究密集波分复用系统中的一种重要的非线性效应——交叉相位调制对系统性能的影响及减小其影响的方法，并研究基于光纤中交叉相位调制的波长转换器。本文首先介绍了光纤通信系统的仿真算法――分步傅立叶方法及其改进形式，并介绍了本文中主要使用的仿真平台：VPI公司的VPITransmissionmaker（原名PTDS，Photonic Transmission Design Suite）。在第二章研究了单信道40Gbps光纤通信系统的优化设计方案及色散补偿方案对系统性能的影响。交叉相位调制是高速多信道光纤通信系统中考虑的一种主要的非线性效应。它与色散共同作用，会导致接收端光脉冲的变形（强度起伏）、光脉冲的时间抖动以及信道的频谱扩展，这些后果都会限制系统的性能。第三章针对交叉相位调制效应进行了研究。首先讨论了在不同色散管理方案下平均场方法的应用，该方法在不降低仿真精度的情况下大大缩减了所需运算量。其次从理论上推导了在色散管理系统中由于交叉相位调制与色散互作用引起的脉冲强度起伏的滤波器模型，根据此模型得到了系统的优化色散补偿方案。通过仿真也研究了波分复用系统中由于交叉相位调制效应引起的幅度抖动从而导致系统性能的恶化；交叉相位调制引起的时间抖动对系统性能也有较大影响，利用拉格朗日变分方法和统计分析的方法，第三章讨论了强色散管理归零码系统中交叉相位调制引起的时间抖动。尽管交叉相位调制对系统性能有较大影响，由于其非线性效应的瞬态响应特性，在高速率全光信号处理方面它却有其独特的用处。本文第四章研究了基于色散位移光纤中交叉相位调制效应的波长转换器，得到了这种波长转换器的一些关键参数及这些参数对波长转换器性能的影响。更多还原

【Abstract】 The fiber-optic systems are developing into wide-band fiber-optic communication systems with huge capacity. As the most widely used method in the backbone communication networks, dense wavelength division multiplexing (DWDM) technology has made remarkable progress. With the increase of the input power and the reduction of the channel separation, nonlinear effects, which has been ignored in the low-bit rate linear systems, has distinguished itself and can not be neglected any more. This work mainly studies the influence of cross phase modulation (XPM) on DWDM systems and schemes to suppress the influence. In addition, all-optical wavelength converter based on XPM in optical fiber is studied. First the commonly used algorithms-Split-step Fourier Method and its enhancement are introduced, as well as the simulation platform mainly used in this work-VPITransmissionmaker by VPI (With its former name PTDS, Photonic Transmission Design Suite). Then the optimal design of a single 40Gbps system and the influence of the dispersion compensation on systems are given. XPM is the mainly considered nonlinear effects in high-speed WDM systems. With dispersion, XPM can induce intensity fluctuations and timing jitter of the pulses in the receiver. It can also cause the spectral spreading of the channel so that crosstalk is introduced. All these effects put a tight limit on the capacity of the systems. In chapter 3, XPM is intensively studied. First, the mean field method is studied in WDM systems with different dispersion maps. By employing this method the computational complexity is greatly reduced without significant sacrifice of the accuracy of the results. Then the filter model is deduced to describe the intensity fluctuation induced by XPM in dispersion managed systems. According to this model, optimal dispersion management schemes are got. The amplitude fluctuation and according system performance degradation induced by XPM is also studied through numerical simulation. The timing jitter caused by XPM can also have great impact on system performance. By employing Lagrangian variational method and statistical method, the timing jitter caused by XPM in strong dispersion managed RZ systems is studied in chapter 3.Although XPM can cause system performance degradation, it finds significant applications in all-optical high speed signal processing, since its response time is very<WP=7>short. A kind of wavelength converter based on XPM in dispersion shifted fiber(DSF) is studied in chapter 4, where the critical parameters and their influence on the performance of the wavelength converter are studied.更多还原