1 x 10 波長選擇開關系統建模與驗證

Abstract

在這個資訊爆炸的時代，元宇宙開啟的虛擬世界加速普及到我們的日常生活中，對於整個通訊網路來說，面臨了巨大的頻寬壓力。想要應對這樣的變化，將整個網路全面光纖化，建設大一統的全光網路（AON, All Optical Network）是一個可行的解法。 全光網路的演進過程分為三個階段，而現今進展到的第三階段，傳輸節點引入光交換，即為引入可調式光塞取多工器（Reconfigurable Optical Add/Drop Multiplexers, 簡稱ROADM）和光交叉連接（optical cross-connect, 簡寫OXC）。而ROADM 技術的出現，使光網路開始具備全互聯的交換功能，隨著時代不斷的進步， ROADM也歷經了三個階段的發展，使得交換功能越來越齊全，組態網路越來越靈活。第三代ROADM涵蓋了波長無關、方向無關、無阻塞的功能，通常以CDC-ROADM表示（colorless, direction-less, contention less ROADM）。而波長選擇光開關（WSS）正是組成第三代ROADM的核心器件，可將波長信號分插到任意通道進行傳輸，具有很高的自由度。 本論文提出以LCoS-SLM 加上均勻性優化的遞迴傅立葉變換演算法（IFTA），並利用光學模擬軟體優化光學系統元件參數，形成1 x 10的波長選擇開關（WSS）系統，以達成光通訊網路之訊號傳播節點的目的，輸入光源可偏轉至10個任意的單光纖端口，亦可同時分光至10 道光纖端口。 在此研究中以IFTA演算法，達成靈活的相位調製；且將光交換機的單波長演變到多波長，以達到波長選擇之目標；使用單模光纖，以貼合近代光通訊高頻傳輸之需求；優化均勻性IFTA演算法，使不均勻度下降約10個百分比；整體系統尺寸從45 cm縮減至28 cm，有利於現今工業化社會需求；以凸透鏡取代柱狀透鏡，使LCoS利用率增加，對應使繞射平面上升，提高耦合效率與不均勻度。

In this era of information explosion, the virtual world expanded by the Metaverse is rapidly spreading into our daily life, for the entire communication network, the limitation of bandwidth is facing a huge pressure. To face such challenges, it is a feasible solution to turn the entire network into fiber optics and build an All Optical Network. The evolution process of All Optical Network is divided into three stages, and the third stage, which is Reconfigurable Optical Add/Drop Multiplexers （ROADM）and Optical Cross Connect（OXC）. The emergence of ROADM technology has enabled optical networks to have fully interconnected switching functions. With the continuous progress of the times, ROADM has also undergone three stages of development, making the switching functions more complete and more flexible. The third-generation ROADM covers colorless, direction-less, and contention less functions, usually expressed as CDC-ROADM. The wavelength selective switch（WSS）is the most important component of the third-generation CDC-ROADM, which can add and drop wavelength signals to any channel for transmission, with a high degree of flexible. This paper proposes an iteration Fourier transform algorithm for homogeneity optimization by analogy to LCoS-SLM, and uses optical simulation software to optimize the parameters of optical system components to form a 1 x 10 wavelength selective switch system. This system achieves the purpose of the signal propagation node of the optical communication network. The input source can be deflected to 10 arbitrary single fiber ports, and can also be split to 10 fiber ports at the same time. In this paper, the IFTA is used to achieve flexible phase modulation; and the single wavelength of the optical switch is evolved to multi-wavelength to achieve the goal of wavelength selection; single-mode fiber is used to meet the needs of high-frequency transmission of modern optical communications; optimize the uniformity IFTA to reduce the non-uniformity by about 10%; the overall system size is reduced from 45 cm to 28 cm, which is beneficial to the needs of today's industrialized society; the use of convex lenses instead of cylindrical lenses increases LCoS utilization, corresponding to the diffraction plane rises to improve the coupling efficiency and uniformity.