啁啾光纤光栅在通信系统中的理论研究与应用

发布时间：2018-05-12 04:52

本文选题：啁啾光纤光栅 + 光学特性　；参考：《江南大学》2014年硕士论文

【摘要】：随着光通信产业的迅猛发展，光纤光栅是近年来发展最为迅速的光无源器件之一，而啁啾光纤光栅具有非线性小、插入损耗低、结构紧凑和能兼容光纤等优势，在光通信领域应用非常广泛。因此，逐步解决光纤光栅目前在光通信理论和应用中所存在的各类关键问题必将会给光纤通信领域带来巨大的改变。本文主要针对光纤光栅的光学特性和高速传输系统中的色散补偿进行了详细阐述。首先，论文详细介绍了光纤光栅(FBG)的分类和基本理论。以耦合模理论为基础，利用传输矩阵法，详细分析了不同参数下的均匀光纤光栅(UFBG)、切趾光纤光栅和啁啾光纤光栅(CFBG)的光学特性。从中可以分析到，光纤光栅反射率、边模抑制比受光纤光栅长度、折变量和啁啾系数的影响规律。与光栅长度和啁啾系数相比，光栅折变量的数值对3dB带宽的影响很大。另外，针对啁啾光纤光栅进行了变迹处理，使用两种常用的变迹函数获得了较理想的光学特性，在此基础上构造了一种新的变迹函数，与两种常用的变迹函数进行对比分析。通过对比发现，采用新的变迹函数进行变迹之后的啁啾光纤光栅的光学特性最理想。接着，，从理论上简要分析了单模光纤中的色散，光纤的总色散是由材料色散、波导色散和折射率分布色散组成。利用Optisystem软件设计了高速传输系统的色散补偿仿真实验图，对比了前置色散补偿、后置色散补偿和对称色散补偿三种色散补偿方式对高速传输系统的色散补偿效果，同时分析了三种色散补偿方式下的误码率与入纤功率的关系。当入纤功率较小时，信噪比比较差，误码率也会比较高；随着入纤功率的增加，噪音相对信号变小了，因此系统的信噪比也随着增加了，误码率也随之变小了；但是随着光功率不断的增加，非线性对系统的影响越来越大，误码率也随之变大。最后，设计了一个40/100/160Gb/s的光纤传输系统，通过对不同的速率、传输距离、占空比、脉冲形状和不同的传输模式对光纤传输系统的三阶色散(TOD)效应影响的分析，得出了三阶色散导致脉冲展宽，脉冲边缘产生震荡，同时脉冲中心会产生时域偏移，随着速率的增加，脉冲中心时域偏移也会变大，脉冲中心时域偏移也受占空比、脉冲形状和光纤类型影响。
[Abstract]:With the rapid development of optical communication industry, fiber grating is one of the most rapidly developing optical passive devices in recent years, and chirped fiber grating has the advantages of small nonlinearity, low insertion loss, compact structure and compatible optical fiber. It is widely used in the field of optical communication. Therefore, gradually solving all kinds of key problems existing in optical communication theory and application of fiber Bragg grating will bring great changes to the field of optical fiber communication. The optical properties of fiber gratings and dispersion compensation in high-speed transmission systems are discussed in detail in this paper. Firstly, the classification and basic theory of FBG are introduced in detail. Based on the coupled mode theory, the optical properties of uniform fiber grating (UFBG), apodized fiber grating (FBG) and chirped fiber grating (CFBG) with different parameters are analyzed in detail by using the transfer matrix method. It can be concluded that the reflectivity of fiber grating and the ratio of side mode suppression are affected by the length of fiber grating, the refractive variables and the chirp coefficient. Compared with the grating length and chirp coefficient, the value of the grating refractive variable has a great influence on the 3dB bandwidth. In addition, the chirped fiber gratings are apodized, and the ideal optical properties are obtained by using two kinds of commonly used apodization functions. On this basis, a new kind of apodization function is constructed and compared with the two kinds of commonly used apodization functions. By comparison, it is found that the chirped fiber grating with a new apodization function is the most ideal. Then, the dispersion in single-mode fiber is analyzed in theory. The total dispersion is composed of material dispersion, waveguide dispersion and refractive index distribution dispersion. The simulation diagram of dispersion compensation for high speed transmission system is designed by using Optisystem software. The dispersion compensation effects of three dispersion compensation modes, namely precompensation, post compensation and symmetrical compensation, are compared. At the same time, the relationship between BER and fiber power under three kinds of dispersion compensation methods is analyzed. When the input power is small, the signal-to-noise ratio (SNR) is poor, and the bit error rate (BER) will be higher. With the increase of the input power, the relative noise signal becomes smaller, so the signal-to-noise ratio of the system increases with the increase of the SNR, and the bit error rate becomes smaller. However, with the increasing of optical power, the influence of nonlinearity on the system becomes more and more, and the bit error rate becomes larger. Finally, a fiber optic transmission system based on 40/100/160Gb/s is designed. The effects of different rates, transmission distance, duty cycle, pulse shape and transmission mode on the third order dispersion (Tod) effect of optical fiber transmission system are analyzed. It is concluded that the third-order dispersion results in pulse broadening, pulse edge oscillation and pulse center migration. With the increase of the rate, the pulse center time-domain migration will also become larger, and the pulse center time-domain migration will also be duty cycle. Pulse shape and fiber type influence.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.1

【参考文献】