發(fā)布時(shí)間：2018-04-19 08:56

  本文選題：光碼分多址 + 光纖光柵��； 參考：《南京大學(xué)》2014年碩士論文

【摘要】：與目前已成熟的通信技術(shù)如波分復(fù)用技術(shù)相比,光碼分多址技術(shù)具有抗干擾、內(nèi)在安全性、成本低、異步接入等許多方面的優(yōu)勢,對(duì)于將來的光網(wǎng)絡(luò)物理層安全和全光高速接入網(wǎng)領(lǐng)域的應(yīng)用前景十分理想。光碼分多址系統(tǒng)的核心器件是編解碼器,它承擔(dān)了對(duì)多路信號(hào)進(jìn)行編碼共享帶寬以及在耦合的信號(hào)中挑選出用戶需要的信號(hào)的重要功能。編碼器的性能會(huì)對(duì)系統(tǒng)性能造成根本性的影響。在眾多編碼器的候選材料中,光纖光柵以它對(duì)光信號(hào)強(qiáng)大而靈活的處理能力以及成本上的優(yōu)勢脫穎而出,大大增強(qiáng)了編碼器的實(shí)用性。目前光碼分多址技術(shù)不斷向?qū)嵱没�方向發(fā)展,制作工藝也是限制它實(shí)用化的重要因素。在已經(jīng)成熟的器件工藝基礎(chǔ)上來尋找實(shí)現(xiàn)編解碼器的方案,顯然是加快其走向?qū)嵱没�的選擇。本文立足于目前發(fā)展中遇到的主要問題,對(duì)基于光纖光柵的編解碼器進(jìn)行了探究,提出了一系列優(yōu)化方案。本文首先對(duì)光碼分多址技術(shù)的優(yōu)點(diǎn)進(jìn)行了探討,介紹了光纖通信特別是光碼分多址技術(shù)的發(fā)展現(xiàn)狀和研究動(dòng)態(tài)。探討了光碼分多址的系統(tǒng)結(jié)構(gòu),分析了各種典型的編解碼方案及各自優(yōu)勢和不足。隨后本文從光纖光柵的原理和分析計(jì)算模型出發(fā),總結(jié)并探討了光纖光柵對(duì)光信號(hào)的處理功能,光纖光柵以其強(qiáng)大而靈活的功能成為編解碼器的理想材料。探討了光纖光柵的主要制作技術(shù)以及制作平臺(tái)的搭建。分析了光纖光柵在編解碼器中的典型應(yīng)用,提出了其在傳統(tǒng)應(yīng)用中的缺點(diǎn)。為了解決傳統(tǒng)光纖光柵在對(duì)制作上藝精度的嚴(yán)苛要求以及制作過程的復(fù)雜程度,本文提出了疊印采樣光柵技術(shù)。根據(jù)等效啁啾和等效相位的原理,疊印采樣光柵可以達(dá)到和傳統(tǒng)光柵一樣的編解碼功能,但通過分析其特性發(fā)現(xiàn),與傳統(tǒng)光柵相比,制作更簡單,且成本更低,僅需要-塊相位掩模板以及精度為亞微米級(jí)的操作平臺(tái),即可制作出多個(gè)反射波長,結(jié)構(gòu)更緊湊的,可以滿足各種類型編解碼器的光纖光柵。本文從理論上探討了基于疊印采樣光柵的編解碼器的可行性,設(shè)計(jì)出適用于頻譜幅度編解碼方案的光纖光柵,并進(jìn)行了4用戶,傳輸速率為5Gb.s的系統(tǒng)仿真,結(jié)果證實(shí)了疊印采樣光柵在頻譜幅度系統(tǒng)的適用性。針對(duì)傳統(tǒng)多波長編碼系統(tǒng)最普遍的問題—-色散進(jìn)行了對(duì)系統(tǒng)優(yōu)化的探討,根據(jù)等效啁啾的原理,提出了集成完全色散補(bǔ)償功能的編解碼技術(shù),成功設(shè)計(jì)了適用于頻譜幅度系統(tǒng)的疊印采樣光柵,并完成了4用戶、傳輸速率為5Gb.s,傳輸距離為lOkm的系統(tǒng)仿真。在沒有任何額外的色散補(bǔ)償器件的情況下,我們設(shè)計(jì)的編解碼器解碼出的光信號(hào)無失真情況,沒有任何色散殘留,得到了信號(hào)質(zhì)量與傳統(tǒng)背靠背一致,色散這個(gè)不利因素得到了很好的解決。
[Abstract]:Compared with the current mature communication technology such as wavelength division multiplexing (WDM), optical code division multiple access (OCDMA) has the advantages of anti-interference, inherent security, low cost, asynchronous access and so on.It is very ideal for the future physical layer security of optical network and the application prospect of all optical high-speed access network.The core device of optical code division multiple access (OCDMA) system is the codec, which plays an important role in encoding and sharing bandwidth of multi-channel signals and selecting the signals needed by users in the coupled signals.The performance of the encoder will have a fundamental impact on the performance of the system.Among the candidates for encoder, fiber Bragg grating (FBG) stands out because of its powerful and flexible processing power and cost advantages to optical signal, which greatly enhances the practicability of encoder.At present, optical code division multiple access (OCDMA) technology is developing to the practical direction, and the fabrication technology is also an important factor limiting its practicality.On the basis of the mature device technology, it is obviously the choice to speed up the application of the codec.In this paper, based on the main problems encountered in the development of fiber Bragg grating-based encoder and decoder, a series of optimization schemes are proposed.In this paper, the advantages of optical code division multiple access (OCDMA) technology are discussed, and the development and research trends of optical fiber communication, especially optical code division multiple access (OCDMA) technology are introduced.The system structure of optical code division multiple access (OCDMA) is discussed, and various typical coding and decoding schemes are analyzed as well as their respective advantages and disadvantages.Then, based on the principle of fiber grating and the analysis and calculation model, this paper summarizes and discusses the processing function of optical signal by fiber grating. Fiber grating is the ideal material for encoder and decoder with its powerful and flexible function.The main fabrication technology of fiber grating and the construction of fabrication platform are discussed.The typical applications of fiber Bragg gratings in codec are analyzed, and their shortcomings in traditional applications are presented.In order to solve the strict requirements of the traditional fiber grating on the fabrication accuracy and the complexity of the fabrication process, the overprint sampling grating technology is proposed in this paper.According to the principle of equivalent chirp and equivalent phase, the overprinted sampling grating can achieve the same coding and decoding function as the traditional grating, but by analyzing its characteristics, it is found that compared with the traditional grating, the fabrication is simpler and the cost is lower.Only a block phase mask and an operating platform with sub-micron precision can be used to produce multiple reflection wavelengths, which are more compact and can satisfy various types of encoder and decoder fiber Bragg gratings.In this paper, the feasibility of the codec based on overprinted sampling grating is discussed theoretically, and a fiber grating suitable for spectrum amplitude coding and decoding scheme is designed, and the system simulation of 4 users with transmission rate of 5Gb.s is carried out.The results confirm the applicability of the overprinted sampling grating in the spectrum amplitude system.Aiming at the most common problem of traditional multi-wavelength coding system-dispersion, the optimization of the system is discussed. According to the principle of equivalent chirp, a coding and decoding technique integrating the function of complete dispersion compensation is proposed.The overprint sampling grating suitable for spectrum amplitude system is designed successfully, and the system simulation of 4 users with transmission rate of 5Gb. S and transmission distance of lOkm is completed.In the absence of any additional dispersion compensation devices, our designed codec decodes the optical signal without distortion, without any dispersion residue, and the quality of the signal is consistent with the traditional back-to-back.The disadvantage of dispersion is well solved.
【學(xué)位授予單位】：南京大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN929.1

【參考文獻(xiàn)】

相關(guān)博士學(xué)位論文 前1條

1 戴一堂;新型光纖布拉格光柵的研究與應(yīng)用[D];清華大學(xué);2006年

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本文編號(hào)：1772425