基于光纤非线性效应的码型转换研究

发布时间：2018-06-07 10:19

本文选题：非线性效应 + 码型转换　；参考：《电子科技大学》2017年硕士论文

【摘要】：因为电子通信设备对输入功率和逻辑转换速率等有一定的限制,不能满足人们对更高速率、更长带宽通信网络的需要。于是研究者就展开了光通信的研究。而码型转换器是光通信中重要的通信设备。非归零码(Non-Return-to-Zero,NRZ)因为传输距离短且有较高的色散容忍度而适用于短距离WDM系统中;而归零码(Return-to-Zero,RZ)因为拥有较好的非线性容忍度而常应用于TDM中。因此NRZ码和RZ码之间的转换有助于实现WDM和TDM系统之间的通信交流。本文利用的核心非线性效应是四波混频,并结合MATLAB仿真软件实现NRZ到RZ的码型转换,主要内容和结果如下:(1)从光传输方程出发,分析耦合方程,重点说明了本文所采用的码型转换依据的核心非线性效应,即简并FWM,并对码型转换的原理进行了介绍。(2)设计出了光电码型转换仿真结构装置。该方案能完成光NRZ到电RZ的转换。同时,从时域、频域和眼图进行MATLAB仿真,证明了码型转换的成功实现。并分析了输入泵浦光功率和输入时钟宽度对生成的RZ信号的影响。以及交换输入泵浦和NRZ信号位置后的码型转换仿真。结果表明:交换输入泵浦和NRZ信号的位置都能很好的实现码型转换。电域下得到的两路RZ信号的功率将会随着输入泵浦光功率的增加而增加。并且,得到的两路RZ信号的时间宽度也会随着输入时钟宽度的增加而增加。整个装置在输入功率很小的情况下就可以发生。整个转换速率是40 Gb/s。(3)设计出了基于M-Z干涉结构的全光码型转换方案。并采用MATLAB仿真验证了从NRZ到RZ全光码型转换的成功实现。采用和光电码型转换相同的讨论分析法,得出了类似的结论,差别是能够得到3路RZ信号。此外,还在此基础上,仿真讨论了XPM和SPM对转换过程的影响。结果表明,这两种非线性效应会造成干涉不完全,影响码型转换。验证完成40 Gb/s的NRZ到3*40 Gb/s RZ的转换。(4)设计出了基于Sagnac干涉结构的全光码型转换方案。采用和M-Z干涉装置相同的分析方法。区别M-Z方案,结果发现:当交换泵浦和NRZ码的位置时,不能实现码型转换。并且,不会存在干涉不完全现象,码型转换质量很好。整个转换速率是40 Gb/s。(5)对比总结本文设计的三种码型转换方案。
[Abstract]:Because electronic communication equipment has some limitations on input power and logic conversion rate, it can not meet the needs of higher rate and longer bandwidth communication network. So the researchers began the study of optical communication. Code converter is an important communication equipment in optical communication. Non-Return-to-Zero NRZ) is suitable for short range WDM systems because of its short transmission distance and high dispersion tolerance, and it is often used in TDM because of its good nonlinear tolerance. So the conversion between NRZ code and RZ code is helpful to realize the communication between WDM and TDM system. The core nonlinear effect used in this paper is four-wave mixing, and the NRZ to RZ code type conversion is realized with MATLAB simulation software. The main contents and results are as follows: 1) starting from the optical transmission equation, the coupling equation is analyzed. The core nonlinear effect of the code type conversion in this paper, that is, degenerate FWM, is emphatically explained, and the principle of the code type conversion is introduced. This scheme can complete the conversion of optical NRZ to electrical RZ. At the same time, the MATLAB simulation from time domain, frequency domain and eye diagram proves the successful realization of code conversion. The effects of input pump power and input clock width on the RZ signal are analyzed. And after switching input pump and NRZ signal position simulation. The results show that both the input pump and the position of the NRZ signal can be converted well. The power of the two RZ signals in the electric domain will increase with the increase of the input pump power. Moreover, the time width of the two RZ signals will increase with the increase of the input clock width. The whole device can happen when the input power is very low. The whole conversion rate is 40Gb / s. 3) an all-optical code conversion scheme based on M-Z interference structure is designed. The MATLAB simulation is used to verify the successful realization of all optical conversion from NRZ to RZ. Using the same discussion analysis method as optoelectronic code conversion, a similar conclusion is obtained. The difference is that three RZ signals can be obtained. In addition, the influence of XPM and SPM on the conversion process is simulated. The results show that these two nonlinear effects will result in incomplete interference and affect the pattern conversion. It is verified that the conversion from 40 Gb/s NRZ to 40 Gb/s RZ is completed. (4) A scheme of all-optical code conversion based on Sagnac interference structure is designed. The analysis method is the same as that of M-Z interferometer. By distinguishing M-Z scheme, it is found that when the pump is switched and the position of the NRZ code is switched, the code conversion cannot be realized. Moreover, there is no interference incomplete phenomenon, and the quality of code conversion is very good. The whole conversion rate is 40 GB / s. 5) the three schemes designed in this paper are compared and summarized.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.1

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