應用於光纖通訊之極化多樣性傳輸結構

Abstract

隨著科技的發展，網路將提供越來越多多樣化的服務，包括線上收看各種視訊影片、即時影音語音談話、線上網路遊戲等，人們對於傳輸流量的速度、品質的要求，及對網路的依賴性也越來越大。由於光通訊技術的發展，很多過去無法達到的頻寬限制已被突破，我們的網路科技也臻至一個高點。然而由於網路的普及化，許多研究學者仍致力於開發新的傳輸演算法，以達到大眾對頻寬的需求。在WDM技術被廣泛運用之後，如何在其之上做改善成了主要的課題，本論文所闡述”利用光之極化多樣傳輸結構”就是一個相當有潛力的方法。 光之極化多樣傳輸結構為利用光在光纖中所擁有不同的極化狀態，作為編碼演算的一種傳輸系統，本論文研讀了有關Polarization Shift-Keying相關文獻，並且提出了一新式發射器結構，僅用光之線性極化狀態作為編碼，使發射器的成本降至最低，並且首度將極化多模色散Polarization Mode Dispersion考慮至此系統之中，此外，我們利用 Matlab數學軟體模擬比較我們提出的結構及在文獻中的結構，最後以一個初步的實驗來證明我們系統的可行性。

With the development of technology, more and more diverse service are provided through internet, such as various online TV or video, real time voice and video interaction, and online games, etc.. People tend to depend more and more on the internet. Meanwhile, The transmission capacity and the quality requirement is becoming stronger as well. Thanks to the development of optical communication technology, plenty of transmission bandwidth requirements have been fulfilled. However, as the internet spreads over and over the world and among the society, researchers are still devoting themselves to create new transmission algorithm in order to meet people’s needs of capacity. After the WDM (Wavelength Division Multiplexing) is widely used in the State-of-the-Art transmission systems, the way to improve the data capacity on WDM becomes an important issue to many researchers and engineers. The polarization diversity scheme we brought out in this thesis is a promising candidate. In the polarization diversity schemes, the different states of polarization (SOP) of light are used to encode the binary data instead of the amplitude of light. We surveyed related literatures of Polarization Shift Keying and propose a new transmitter architecture which employs only the linear SOPs of light as the encoder. In this way, the transmitter complexity and cost can be reduced to minimal. Besides, we first introduce the consideration of Polarization Mode Dispersion as a degrading factor to the polarization diversity schemes. We compare also our proposed schemes with the conventional 4-PolSK scheme in the literature. A preliminary experiment is performed to analyze the feasibility of our proposed system.