【作者】 李岩；

【导师】 井文才； 周革；

【作者基本信息】 天津大学 ， 光学工程， 2005， 硕士

【摘要】 目前,动态可调节色度色散(CD)补偿技术已经成为40Gb/s或更高速光纤通信系统中的一项关键技术。动态色散补偿需要一种结构简单且有效的色度色散探测方法,监测系统中累积色度色散值,获得反馈信号,以控制动态可调节色度色散补偿系统中的可调节色度色散补偿器件。本文提出了一种无需调制发送端、易于实现并且成本较低的色散反馈信息提取方法,通过探测传输光脉冲某一频率周围窄带处的电功率值实现光纤通信线路中色度色散的实时监测,用以作为反馈信号。在40Gbit/s光纤通信系统中,选用12GHz作为窄带中心频率,系统色度色散反馈值的测量范围可达130ps/nm,平均测量精度可达5.2ps/nm。本文主要完成以下几项工作: 1.从理论上分析了色度色散对高斯光脉冲形状和频谱的影响,对不同色散情况下高斯脉冲的时域和频域特性进行了仿真分析。2.讨论了已报导的几种用于动态色度色散补偿的反馈信号获取方法,并对每种方法的优缺点进行了分析。3.对高斯光脉冲经过光电转换器件后的电功率谱与系统累积色散值之间的关系式进行了推导,仿真得到了在不同频点处色散与电功率谱密度的关系曲线。从理论上分析了除色度色散外其他影响电功率值的因素。4.提出用电功率法实现色散反馈信号获取的实验总体结构图,设计了简易的色散模拟装置以及用于40Gbit/s RZ码光纤通信系统的色散反馈信号获取装置。5.分别针对40Gbit/s和10Gbit/s RZ码伪随机光脉冲两种输入序列进行了实验,得到的实验数据与理论曲线基本吻合。更多还原

【Abstract】 Nowadays dynamic tunable chromatic dispersion (CD) compensation has become a key technique in 40Gbit/s and beyond optical fiber communication system. Thus a simple structured and effective chromatic dispersion monitoring method is required. In such a monitoring system the value of chromatic dispersion should be measured,and the feedback signal is acquired to control the tunable CD components in the system. A method to measure dispersion feedback signal is proposed in this thesis. To achieve the real-time monitoring of CD in the optical fiber transmission line, the electrical power of a specific narrow frequency band of a certain optical signal pulse is measured as a feedback signal. In the 40Gbit/s optical fiber communication system used in the experiment, the maximum detectable CD of 130ps/nm and a resolution of 5.2ps/nm were achieved at the narrow band frequency centered at 12GHz. This thesis mainly focuses on the following aspects: 1. From a theoretical viewpoint, the influence of CD on the pulse shape and the spectrum of Gaussian pulses are analyzed. Simulation is performed to analyze the Gaussian pulses in time and frequency domains under different chromatic dispersion conditions. 2. Several reported methods to measure dynamic CD compensation feedback signal are discussed. The pros and cons of each method are analyzed. 3. The equation about the electrical power spectrum and the dispersion value of the Gaussian pulses detected by the photo detector is discussed. The relationship between CD and the electrical power spectrum density at different frequencies was acquired with theoretical analysis and simulation. Furthermore, other factors that affect the electrical power are also analyzed. 4. The experimental structure used to monitor the CD feedback signal using electrical power method is proposed. A CD emulator and a 40Gbit/s RZ code CD detection system were designed and implemented accordingly. 5. Experiments were carried out to test the CDs with 40Gbit/s and 10Gbit/s RZ pseudo-random code optical pulse as the input sequences. The experimental results are in accordance with the theoretical values.更多还原