光通訊網路技術之研究

Studies on Optical Communication Network Technologies

楊蘭治(Lan-Chih Yang)

指導教授 ： 黃建彰

元智大學/電機通訊學院/電機工程學系/博士(2011年)

摘要

本文提出光通訊網路技術相關之研究，我們從光通訊元件著手，首先利用光子晶體的技術提出一種分光器，它是以許多不同大小和型式的空氣洞建構在Si/SiO2/Si架構上的光子晶體，當移動波導中的三角形空氣洞的位置即可調整分光比，此分光器具有低的插入損失、體積小（約34μm2）、設計簡單、成本低且分光效果良好的優點，未來可應用在光纖網路之光交換器上。第二部分我們建構以SOI為基底的光子晶體，利用FDTD模擬的方法將光打入此光子晶體中，當光子晶體作適當排列使光之繞射具有相位奇異點，即可觀測到光漩渦的現象，此現象將來有機會應用在非線性交換器及光纖網路上。而在光通訊網路架構的研究上，我們提出一個CDMA編/解碼器，並找出耦合比k及頻率f之最佳化參數(k, f)值，它因製造簡單、成本低加上編解碼之效果良好，未來可應用在光纖網路上。接著我們建構兩種多通道多波長架構之光交換器，並改變串音及插入損失來分析BER值，發現Dilated Benes 的架構性能較佳，將來可應用在光纖網路上。最後我們分析台灣本島SDH骨幹光纖網路非自復環任一條鏈路中斷時各種復原策略，未來當台灣光纖網路某一段光纖中斷時可應用此復元機制。

關鍵字

分光器 ； 光漩渦 ； 編/解碼器 ； 光波交換網路 ； 保護策略

並列摘要

In this dissertation some study results on the network technologies are proposed for optical communications. We start from the component level in which a novel optical power splitter is shown using photonic crystal structure built on Si/SiO2/Si substrate where three types of air holes are utilized to construct the photonic crystal. This splitter has advantages of low insertion loss, small size (about 34?m2), easy design, and low cost features, and has potential in applications of fiber network cross connection. Next we study the optical vortex phenomenon for the photonic crystal on the SOI structure. The simulation is conducted by launching the light to the photonic crytal using FDTD method. As the diffraction caused by the certain photonic crystal arrangement introduces some optical phase singularities, the vortex phenomena can be observed. The optical vortices may be useful for the development of future optical nonlinear switches with the aid of the strong field at the vortex spot which acts as a switching point in integrated optical circuits. For the optical network architecture, we propose a new dynamic encoder/decoder for fiber CDMA networks. The theoretical models are developed using the Z-transform and E-field response of the dynamic encoder/decoder with an E/O coupler. From simulation studies, we can get some (k, f) parameter combinations to acheieve the optimum performance of the system. The new structure is simple and flexible in producing any other code sequences that are applied for the fiber network. And then, we compare performances for two types of switching configurations through the simulation studies. The Dilated Benes is found to be better than the other one. This information is useful for the optical switching network designs. Finally we analyze the SDH backbone fiber network in Taiwan with non-self-healing ring, and propose a recovery strategy when any communication link fails. This protection scheme can be applied at the beginning of the deployment for the Taiwan SDH fiber network.

並列關鍵字

splitter ； vortex ； encoder/decoder ； optical switching network ； protection strategy

參考文獻

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