节点文献
高速光纤传输系统及新型光路交换网的研究
Research on High-speed Optical Fiber Transmission System and Novel Optical Circuit Switching Network
【作者】 秦曦；
【导师】 简水生；
【作者基本信息】 北京交通大学 ， 通信与信息系统， 2008， 博士
【摘要】 全光网是未来光通信发展的主要方向,是目前光通信研究的热点之一。本论文在国家自然科学基金项目的资助下,围绕全光网的传输和交换两方面展开,主要研究内容包括高速光纤传输系统中的信道内非线性效应、高级相位调制技术、基于啁啾光纤光栅(CFBG)色散补偿的高速系统传输和基于光路交换的全光交换网的实现。在深入研究的过程中,取得了以下主要研究成果:1.首次分析了基于啁啾光纤光栅(CFBG)色散补偿的高速光纤传输系统中的信道内非线性效应。利用微扰法推导出了同时考虑群时延纹波(GDR)和信道内四波混频(IFWM)时信号幅度的计算公式;同时,利用变分法推导出了基于CFBG补偿色散的传输系统中由信道内交叉相位调制(IXPM)引起的相邻脉冲时间抖动的理论模型。并基于这两个模型详细的分析了GDR对信道内非线性效应的影响,所得到的结论对深入研究和设计基于CFBG补偿的高速光纤传输系统具有重要的意义;2.比较了归零码(RZ)、载波抑制归零码、归零-交替反转码以及载波抑制归零-交替反转码对由IFWM所引起的“影子”脉冲(ghost pulse)的抑制能力。所得结论为高速光纤传输系统设计提供了参考;3.分析了归零-差分相位调制传输系统中的相位噪声。详细比较了几种相位噪声对系统性能的影响;推导出了色散预补偿和色散后补偿这两种补偿方式下非线性相位噪声的计算公式,并对这两种色散补偿方式下的相位噪声、功率容限以及最优信号峰值功率进行了详细的分析和讨论,所得结论对相位调制系统设计有实际指导意义;4.实验比较了40Gbit/s非归零码(NRZ)在分别采用CFBG和色散补偿光纤补偿色散的传输系统中的性能;在全组成员的共同努力下,首次实现了基于CFBG色散补偿的40Gbit/sNRZ信号无误码传输500km;5.分析了单驱动z-切调制器无法产生占空比为33%和67%RZ光时钟脉冲的原因,在此基础上提出了一种解决方案,利用该方案得到了占空比分别为25%和56%的40Gbit/s无啁啾RZ光时钟脉冲;6.提出了一种新颖的调节RZ光时钟脉冲宽度的方法,该方法通过改变调制器的啁啾系数实现对脉冲宽度的调节,理论上可以实现的脉冲占空比调节范围为23.8%～33.3%和47.4%～56.1%;7.构建了基于“新型分布式波分纤分光路交换系统”全光交换网构思的演示网。该网络通过引入新型的信令系统从结构上保证了网络的安全性。同时,利用LabVIEW高级程序设计语言编写软件,实现对该网络的节点管理。
【Abstract】 All-optical network (AON) is the major trend of future optical communication, which makes it become one of the hot research areas. Supported by the National Natural Science Foundation of China, we focus our research on the two aspects of AON, transmission and switching. The concrete research contents include the intrachannel nonlinearity effects in high-speed optical fiber transmission system, advanced phase modulation techniques, high-speed transmission of systems with dispersion compensated by chirped fiber Bragg gratings, and realization of the all optical switching network based on Optical Circuit Switching (OCS). And the main achievements of this thesis are listed as follows:1. Intrachannel nonlinearity in high-speed optical fiber transmission systems with dispersion compensated by CFBG is studied for the first time. A theoretical model for the calculation of signal amplitude when GDR and IFWM are both taken into account is deduced by small-field perturbation method. Besides, another theoretical model is proposed for the analysis of timing jitter induced by IXPM in optical fiber communication systems using CFBG as dispersion compensator. Based on these two modes, influence of GDR on intrachannel nonlinearity is studied, in detail. The conclusions are very useful for research and design of CFBG-compensated high-speed optical fiber transmission systems.2. The potential of RZ, CSRZ, RZ-AMI, and CSRZ-AMI to suppress the ’ghost’ pulse induced by IFWM is compared. The conclusion is a good consult for designing of high speed optical fiber transmission systems.3. Phase noise in RZ-DPSK transmission systems is analyzed. The effect of phase noise on transmission systems is compared, in detail. Besides, the formulas to calculate nonlinear phase noise are proposed for both pre-compensation and post-compensation schemes. Based on these formulas, the phase noise, power tolerance and optimal signal peak power of both dispersion compensation schemes are analyzed and discussed in detail, respectively. The conclusions are consultable for design of phase modulation systems.4. Experimental comparison is accomplished between dispersion compensation fiber and CFBG when they are used as the dispersion compensator of 40Gbit/s NRZ transmission systems. And, with the joint efforts of the whole team members, 500km error-free transmission is achieved when the dispersion is compensated by CFBQ for the first time.5. The reason why RZ optical clock pulses with duty cycle of 33% and 67% can’t be generated by single driver z-cut MZM is analysed. And a novel method is proposed and experimental validated.6. A novel method is proposed for tunable width RZ optical clock pulses generation. Numerical simulation shows that by tuning the chirp coefficient of the modulation, RZ optical pulses with duty cycle tunable in the range of 23.8%～33.3% and 47.4%～56.1% will be gotten.7. A demo system based on the conception of "a novel distributed wavelength-divided and fiber-divided OCS system" is established. The security of the system is guaranteed by a novel signaling system. And programming software is complied with LabVIEW for node management of the demo system.