近年來光纖網路迅速發展，包括一般長途骨幹網路、都會型網路和接取網路，是基於光纖通訊技術及光元件的應用。在光元件中，光循環器在雙向光纖傳輸中扮演著相當重要的角色。 本篇論文主要探討進階型2×2光開關的內部結構與工作原理，其架構是利用一顆可逆四埠全通式光循環器結合另外相同一顆或另一顆常見2×2光開關。所提出的進階型2×2光開關擁有互易Bar狀態與非互易Bar/Cross狀態，不同於一般2×2光開關互易性質Bar/Cross狀態。此外它較廣泛使用的一般2×2光開關更具有彈性，因此適合多種不同的應用。 WDM-PONs必然是未來光通訊發展的趨勢。為了確保網路服務的可靠度，如何有效地維護光網路確實是一個重要的課題。因此我們提出一個可提供路徑保護及恢復功能的WDM-PON架構。為了建立相互保護群體，所提的進階型2×2光開關是設置在OLT端以及將ONUs分成兩個群體。此種方案可以減少光元件的使用，以降低整體架構的花費，同時又可以維持饋送線光纖與分配光纖的傳輸。 最後，實驗結果證實所提基於進階型2×2光開關的WDM-PON保護架構之可行性。 In recent years, the rapid development of optical fiber networks, including generic long-distance backbone networks, metropolitan area networks and access networks, is based on the applications of optical fiber communication technologies and optical components. Among optical components, optical circulators play a prominent role in the bi-directional optical fiber communication systems. This thesis mainly discusses the principles and structures of advanced 2×2 optical switches (AOSs) that utilize one reversible four-port cyclic optical circulator to combine another the same or another conventional 2×2 optical switch (COS). The proposed AOS possesses a reciprocal bar state and a nonreciprocal bar/cross state, which is different from the COS with a reciprocal bar/cross state. In addition, it is more flexible than the COS in wide use, so it is suitable for a variety of applications. Wavelength-division-multiplexed passive optical networks (WDM-PONs) must be a trend in the development of optical communications in the future. In order to ensure the reliability of network service, how effectively to maintain optical networks is indeed very important as an issue. Therefore, we proposed a WDM-PON architecture that provides the function of path protection and restoration. To create mutual protection groups, the proposed AOS is set at the optical line terminal (OLT), and the optical network units (ONUs) are divided into two groups. This scheme can reduce the number of optical components to achieve the reduction of an entire system’s cost. Furthermore, the feeder fibers and distribution fibers can be protected simultaneously. Finally, experimental results verify the feasibility of the proposed AOS-based WDM-PON protection architecture.
