【正文】 畢 業(yè) 設(shè) 計(jì)（論 文） 題 目 基 于光子晶體光纖的 WDM 系統(tǒng)的設(shè)計(jì) 姓 名 余文志 學(xué) 號(hào) 0811122121 所在學(xué)院 理學(xué)院 專業(yè)班級(jí) 2021級(jí) 光信 1 班 指導(dǎo)教師 成純富 日 期 2021年 05 月 22 日 湖北工業(yè)大學(xué)理學(xué)院 2021 屆畢業(yè)設(shè)計(jì)（論文） I 摘 要 隨著人類社會(huì)進(jìn)入信息時(shí)代，人們對(duì)信息量的需求不斷提高， 導(dǎo)致 全球信息傳輸量呈級(jí)數(shù)增長(zhǎng)，對(duì)通信網(wǎng) 絡(luò)的帶寬、容量和傳輸速率提出了更高的要求，在這種背景下 WDM技術(shù)應(yīng)運(yùn)而生。在 WDM系統(tǒng)中，理想 的光纖應(yīng)該具有很小的衰減、適當(dāng)?shù)纳?、很低的偏振模色散，較大的有效面積、理想的彎曲損耗特性等。但傳統(tǒng)的光纖很難滿足這些要求，這就限制了光網(wǎng)絡(luò)容量和傳輸速率的進(jìn)一步提高。為了解決這一問題人們開始研究新型光纖，本文所研究的光子晶體光纖就是眾多新型光纖中的一種。理論研究結(jié)果表明這種光纖具有很多優(yōu)良的傳輸特性，如不截止的單模特性、可控的模場(chǎng)面積、靈活的色散特性、可控的波導(dǎo)色散特性、極低的損耗和極低的非線性效應(yīng)等。 光子晶體光 纖以其獨(dú)特的傳輸特性，很好的解決了光纖傳輸中遇到的損耗、色散和非線性等問題，因而近幾年來對(duì)光子晶體光纖的研究備受關(guān)注。 本文利用 Optisystem軟件對(duì)基于光子晶體光纖的 WDM系統(tǒng)的其傳輸性能做了仿真研究，主要研究了以下內(nèi)容： 研究了 光子晶體光纖 WDM系統(tǒng) 光源發(fā)射功率對(duì)其性能的影響 ，側(cè)重 研究 了NRZ碼型和 RZ碼型的 光子晶體光纖 WDM系統(tǒng) 的功率特性 。研究發(fā)現(xiàn) ： 對(duì)于兩種調(diào)制碼型在較低功率時(shí)噪聲對(duì) 系統(tǒng)的影響占主導(dǎo)因素 ，在高功率情況時(shí)非線性效應(yīng)對(duì)系統(tǒng)的 影響占主導(dǎo)，并確定了兩種碼型的最佳發(fā)射功率。 研究了碼 型對(duì) 光子晶體光纖 WDM系統(tǒng) 傳輸性能 的影響 。 研究 發(fā)現(xiàn)在低功率時(shí) NRZ碼型比 RZ碼型的抗噪性能好； 在高功率時(shí) RZ碼型比 NRZ碼型的抗非線性能力強(qiáng)。 RZ碼型更適合在高速速率的長(zhǎng)距離通信系統(tǒng)中使用。 研究了傳輸距離對(duì) RZ碼型 光子晶體光纖 WDM系統(tǒng)的影響。發(fā)現(xiàn)傳輸 距離 的增加，接收的信號(hào)質(zhì)量嚴(yán)重惡化，分析發(fā)現(xiàn)造成傳輸性能的降低是由于級(jí)聯(lián)結(jié)構(gòu)中 EDFA和積累的非線性效應(yīng)引起的。同時(shí)確定其最大傳輸距離為 850km，最佳的傳輸距離為 700km。 研究了色散對(duì)光子晶體光纖 WDM系統(tǒng)的影響。發(fā)現(xiàn)色散 和色散斜率 對(duì)高速長(zhǎng)距離 的 光子晶體光纖 WDM系統(tǒng)影響十分嚴(yán)重，因此在設(shè)計(jì)中必須處理好色散和色散斜率的 補(bǔ)償問題。 關(guān)鍵字 ： 光子晶體光纖、 WDM、 Optisystem、仿真 。 湖北工業(yè)大學(xué)理學(xué)院 2021 屆畢業(yè)設(shè)計(jì)（論文） II Abstract As human society enter the information age, the demands of information continue to increase, leading to exponential growth of global information transmission amount and a higher demand on the munication work bandwidth, capacity and transfer rate, in this context， the technology of WDM es into being. In the WDM system, the ideal fiber should have characteristics of small attenuation, appropriate dispersion, low polarization mode dispersion， large effective area and ideal bending loss. However, the conventional optical fiber is difficult to meet these requirements, which limits further improve the capacity and transfer rate of optical work. To solve this problem, people begin to study new kinds of fiber. Photonic crystal fiber studied in this article is one of them. The theoretical results show that this fiber has many excellent transmission characteristics, such as uncutoff of the singlemode, the controlled mode area, flexible dispersion properties, controllable waveguide dispersion, low loss and very low nonlinear effect. As Photonic crystal fiber has such unique characteristics of transmission, which provided a good solution to the problems of transmission loss, dispersion and nonlinearity in the fiber, thus, in recent years, the study of photonic crystal fiber bees hot point. In this article, we use Optisystem simulation software to study the transmission performance of WDM systems based on photonic crystal fiber. These studies mainly include: First， we study the effect of the laser transmitting power on the transmission performance of the PCF WDM system, focusing on the power characteristics of NRZ pattern and RZ pattern. The study found: for the two modulation pattern, in the case of lowpower, the impact of noise on the system is the dominant factor。 in the case of highpower, the impact of nonlinear effects on the system is the dominant factor, and find the best transmitting launch power of the two patterns. Secondly， we study the influence of the modulation pattern on the transmission performance of the PCF WDM system. The study found: in the case of lowpower, the antinoise performance of the NRZ pattern is better than the RZ 湖北工業(yè)大學(xué)理學(xué)院 2021 屆畢業(yè)設(shè)計(jì)（論文） III pattern。 in the case of highpower, the antinonlinear capability of RZ pattern is stronger than the NRZ pattern. RZ pattern is more suitable for use in highrate and longdistance munication systems. Then, we investigate the influence of the transmission distance on the RZ pattern PCF WDM system. Found that as the increase of the transmission distance, the received signal quality bee badly. We found the EDFA and the accumulation of nonlinear effects are the dominant factors that cause the reduction of the transmission performance. At the same time, we find the maximum transmission distance is 850km, the best transmission distance is 700km. Finally， we explore the impact of the dispersion on the PCF WDM system. Found that the impact of the dispersion and the dispersion slope on the longdistance and highspeed PCF WDM systems is very serious, so dispersion pensation issues and dispersion slope pensation issues must be addressed well in the design. Key words： Photonic crystal fiber, WDM, Optisystem, simulation. 湖北工業(yè)大學(xué)理學(xué)院 2021 屆畢業(yè)設(shè)計(jì)（論文） IV 目 錄 摘要 ..................................................................................................................................I Abstract ........................................................................................................................... II 第一章 緒論 .................................................................................................................... 1 光纖通信技術(shù)發(fā)展和現(xiàn)狀 .................................................................................... 1 光子晶體光纖研究背景及發(fā)展 ............................................................................. 2 光子晶體光纖研究背景 .............................................................................. 2 光子晶體光纖的發(fā)展 ................................................................................. 3 WDM技術(shù)發(fā)展及現(xiàn)狀 ......................................................................................... 4 論文內(nèi)容安排 ..................................................................................................... 5 第二章 光子晶體光纖 ...................................................................................................... 6 光子晶體光纖的概念和分類 .....................................................................