本論文主要探討磁光元件的原理及結構與其延伸設計，使得一般商用光隔離器和光循環器皆具有可逆方向的功能。在衰減原理分析及磁力模擬後，設計出外置式磁力控制單元裝設在光隔離器，以達成電控可調光衰減器的功能。此外我們自製出4埠可逆光循環器，同時也提出非互易(non-reciprocal)光開關以及可重置組態(reconfigurable)光放大器。
    最後我們提出可提供線路保護及恢復機制WDM-PON (wavelength-division-multiplexed passive optical network)架構。它與眾不同的特徵包括在OLT (optical line terminal) 設置一組非互易光開關，以及將ONUs (optical network units)分成兩個群體，此兩群體相互保護。當發生光纖線路故障時，由OLT端監測單元控制光開關切換至對應的保護狀態，則上/下傳光訊號完成路徑保護，以恢復正常傳輸。我們將光開關設置在OLT端，可以減少光開關的使用數量，以降低整體架構的花費，並且支線光纖與分配光纖同時皆可以被保護。

This thesis mainly discusses the principles and structures of magneto-optic components, and their extended designs, while enable commercialized optical isolators and optical circulators to work at the reverse direction. After theoretical analysis and magnetic architecture simulation, we designed external magnetic control units, while were assembled with optical isolators, to achieve the variable optical attenuators through electric control. Furthermore, we realized a 4-port reversible optical circulator and proposed its related applications that include a non-reciprocal optical switch and reconfigurable optical amplifiers.
Finally, we proposed a wavelength-division-multiplexed passive optical network (WDM-PON) architecture that provides path protection and traffic restoration. The architecture is unique in that it has a non-reciprocal optical switch at the optical line terminal (OLT), and the optical network units (ONUs) are separated into two groups to protect each other. When a fiber path breaks, the upstream/downstream optical signals can be rerouted to a protection path by switching the non-reciprocal optical switch. This scheme can reduce the number of optical switches and the cost of system. Furthermore the feeder fibers and distribution fibers can be protected simultaneously.

目錄
第一章 簡介...................................................................................................1
    1.1 前言..................................................................................................1
    1.2 研究動機..........................................................................................4
    1.3 論文架構..........................................................................................5
第二章 使用光隔離器所構成之可調式光衰減器.......................................6
    2.1 簡介..................................................................................................6
    2.2 光隔離器原理及基本特性..............................................................7
        2.2.1 光學晶體介紹.......................................................................8
2.2.2 極化非相關型光隔離器.....................................................12
2.3 磁光VOA工作原理......................................................................14
2.4 模擬分析與元件設計....................................................................21
2.4.1 模擬分析.............................................................................21
2.4.2 元件設計.............................................................................29
第三章 可逆式光循環器與新式2 × 2光開關...........................................34
    3.1 簡介................................................................................................34
    3.2 4-port 光循環器.............................................................................35
    3.3 可逆式光循環器............................................................................38
        3.3.1 磁性材質簡介.....................................................................38
        3.3.2 可逆式光循環器工作原理.................................................40
        3.3.3 可逆式光循環器設計.........................................................51
    3.4 新式2 × 2光開關...........................................................................55
        3.4.1 光開關簡介.........................................................................55
        3.4.2 新式2 × 2光開關設計........................................................59
第四章 新式光放大器與WDM-PON 線路保護技術..............................62
  4.1 新式光放大器之設計...................................................................62
       4.1.1 前言.......................................................................................63
       4.1.2 摻鉺光纖放大器簡介...........................................................67
       4.1.3 可逆式光放大器之設計.......................................................71
    4.2 WDM-PON 線路保護技術...........................................................74
    4.2.1 先前技術介紹 .....................................................................74
       4.2.2 使用新式2 × 2光開關之線路保護技術..............................82
第五章 實驗與模擬結果.............................................................................90
5.1 可調式光衰減器............................................................................90
       5.1.1可調式光衰減器之製作........................................................90
       5.1.2 可調式光衰減器參數量測...................................................92
    5.2 可逆式光循環器............................................................................99
       5.2.1 可逆式光循環器驅動電路製作.........................................100
       5.2.2可逆式光循環器參數量測..................................................104
       5.2.3 新式2 × 2 光開關參數量測..............................................110
   5.3 新式光放大器................................................................................113
       5.3.1 光放大器基本特性量測.....................................................113
       5.3.2 新式光放大器功能驗證.....................................................117
   5.4 WDM-PON線路保護.....................................................................123
       5.4.1 模擬設置.............................................................................123
       5.4.2 模擬結果與分析.................................................................124
第六章 結論...............................................................................................133
    6.1 成果與討論..................................................................................133
    6.2 未來研究方向..............................................................................134
參考文獻.....................................................................................................136




圖目錄
圖1.1 光隔離器概念圖.................................................................................2
圖1.2 磁光開關示意圖.................................................................................3
圖1.3 磁場感測器示意圖.............................................................................3
圖2.1 光隔離器功能示意圖.........................................................................8
圖2.2 法拉第磁光效應示意圖.....................................................................9
圖2.3 負單軸晶體內O-ray與E-ray各方向速度.......................................10
圖2.4 入射光與負單軸晶體光軸既不垂直也不平行...............................10
圖2.5 入射光與負單軸晶體光軸平行.......................................................11
圖2.6 入射光與負單軸晶體光軸垂直.......................................................11
圖2.7 線性偏振光經λ/2片的結果.............................................................12
圖2.8 一般極化非相關型光隔離器 (a)正向傳輸 (b)反向傳輸..............13
圖 2.9 雙級極化非相關光隔離器..............................................................14
圖2.10 經線性偏振片的光強度變化.........................................................15
圖2.11 入射光E經線性偏振片-2後之光強度變化..................................15
圖2.12 一般光隔離器正向傳輸光路徑圖.................................................16
圖2.13 線性偏振光分解成O-ray與E-ray..................................................16
圖2.14 法拉第旋轉子的旋轉角度增加θ...................................................17
圖2.15 單級、雙級光隔離器模擬設置.......................................................19
圖2.16 模擬法拉第旋轉子旋轉角度與輸出光功率的關係圖.................19
圖2.17 模擬法拉第旋轉子旋轉角度與光衰減量的關係圖.....................20
圖2.18 光隔離器表面磁力分布.................................................................21
圖2.19 光衰減運作模式 (a)單顆磁鐵情況 (b)雙顆磁鐵情況................22
圖2.20 不同磁鐵所造成的光衰減量.........................................................23
圖2.21 Free-Space Isolator...........................................................................25
圖2.22 模擬光隔離器內部磁場分布.........................................................26
圖2.23 模擬外加磁鐵對光隔離器內部磁場分布的影響.........................27
圖2.24 不同磁場強度與法拉第旋轉子旋轉角度的關係圖.....................27
圖2.25 光隔離器的法拉第旋轉子旋轉方向與光路徑的關係圖.............29
圖2.26 磁光開關示意圖.............................................................................30
圖2.27 本章所提出VOA結構....................................................................31
圖2.28 在光隔離器表面皆包覆導磁材料.................................................31
圖2.29 依照圖2.28的結構模擬結果.........................................................33
圖2.30 依照圖2.27的結構模擬結果.........................................................33
圖3.1 3-port光循環器之光路徑示意圖......................................................34
圖3.2 4-port光循環器之光路徑示意圖......................................................35
圖3.3 4-port光循環器路徑圖 (a)埠1的狀況 (b)埠2的狀況 (c)埠3的狀況 (d)埠4的狀況...............................................................................37
圖3.4 可逆式光循環器之示意圖...............................................................41
圖3.5 可逆式光循環器路徑圖 (a) 埠1的狀況 (b) 埠2的狀況 (c) 埠3的狀況 (d) 埠4的狀況...................................................................43
圖3.6 4-port光循環器表面磁通量密度分佈..............................................45
圖3.7 磁石切換光循環器之示意圖 (a)正向切換至反向 (b)反向切換至正向...................................................................................................45
圖3.8 表3.3半硬磁材料之磁滯曲線.........................................................46
圖3.9 光循環器之內部garnet示意圖........................................................47
圖3.10 正向循環狀態的磁通密度分佈圖.................................................48
圖 3.11 不同間距所得到磁通密度趨勢圖................................................48
圖3.12 模擬光循環方向被逆轉.................................................................49
圖3.13 光循環器的反向循環磁通密度分佈圖.........................................50
圖3.14 模擬光循環方向由反向循環改變至正向循環.............................50
圖3.15 線圈未包覆磁性區域L1、L2..........................................................52
圖3.16 線圈剛好包覆磁性區域L1、L2......................................................52
圖3.17 線圈範圍超出磁性區域L1、L2......................................................53
圖3.18 線圈分別位於磁性區域L1、L2......................................................53
圖3.19 模擬正向循環切換至反向循環狀態之最佳磁通密度.................55
圖3.20 一般光塞取分波多工濾波器.........................................................57
圖3.21 常見2×2光開關切換狀態..............................................................59
圖3.22 非互易性2×2 bar-cross光開關.......................................................60
圖3.23 切換單一顆光循環器之狀態.........................................................61
圖4.1 文獻[18]的系統架構圖.....................................................................64
圖4.2 修正型EDFA及OTDR的偵測配置................................................64
圖4.3 文獻[20] 的系統架構圖...................................................................65
圖4.4 保護機制 (a)1+1保護 ( b)1:1保護 ( c)1:N保護...........................66
圖4.5 雙向傳輸之 1:1保護機制................................................................67
圖4.6 摻鉺離子的能階圖...........................................................................68
圖4.7 一般摻鉺光纖放大器之結構...........................................................69
圖4.8 可逆式光放大器之架構圖(a) 可逆式光放大器(b)增益元件........71
圖4.9 上下行光在不同狀態下之路徑圖...................................................72
圖4.10 進階型可逆式光放大器之路徑圖.................................................73
圖4.11 雙向傳輸之簡易1:2保護機制.......................................................74
圖4.12 文獻[25]之系統保護設置圖...........................................................76
圖4.13 文獻[25]之波長配置圖..................................................................76
圖4.14 文獻[25]故障發生時保護路徑.......................................................77
圖4.15 文獻[26]之系統保護設置圖...........................................................78
圖4.16 文獻[26]之波長配置圖...................................................................78
圖4.17 文獻[27]之系統保護設置圖...........................................................80
圖4.18 文獻[27]之波長配置圖...................................................................80
圖4.19 文獻[27]ONU端設置圖(a)正常狀況(b)故障狀況........................81
圖4.20 文獻[27]光纖使用圖(a)正常狀況(b)保護狀況..............................81
圖4.21 新式保護架構之波長配置圖.........................................................82
圖4.22 新式保護架構之正常模式.............................................................84
圖4.23 故障發生時切換至保護路徑(Group2) ..........................................86
圖4.24 故障發生時切換至保護路徑(Group1) ..........................................87
圖5.1 (a)電磁吸鐵裝設示意圖(b)可調式光衰減器成品實體圖...............91
圖5.2 Small type VOA的光衰減範圍與驅動電流關係圖.........................92
圖5.3 Big type VOA的光衰減範圍與驅動電流關係圖.............................93
圖5.4 VOA在不同衰減量下之極化相關損失...........................................94
圖5.5 VOA在不同衰減量下之平坦度.......................................................95
圖5.6 VOA響應時間量測...........................................................................96
圖5.7 衰減量10 dB範圍，隨著時間VOA衰減量與溫度的變化.............97
圖5.8 衰減量20 dB範圍，隨著時間VOA衰減量與溫度的變化.............97
圖5.9 可逆式光循環器之完成品...............................................................99
圖5.10 可逆式光循環器的驅動電路方塊圖...........................................100
圖5.11 H- bridge電路.................................................................................100
圖5.12 抑制反電動勢示意圖...................................................................101
圖5.13 可逆式光循環器的驅動電路圖...................................................102
圖5.14 固定脈衝長度訊號產生方塊圖...................................................103
圖5.15 訊號產生模擬結果.......................................................................104
圖5.16 量測反應時間之實驗設置圖.......................................................106
圖5.17 觸發脈衝與循環方向狀態圖.......................................................106
圖5.18 (a)正向循環切換至反向循環(b)反向循環切換至正向循環.......107
圖5.19 埠2切換狀況實驗結果................................................................108
圖5.20 埠3切換狀況實驗結果................................................................108
圖5.21 正緣觸發訊號出現時，埠2切換狀態圖......................................109
圖5.22 負緣觸發訊號出現時，埠2切換狀態圖......................................110
圖5.23 模式一及模式二狀態示意圖.......................................................111
圖5.24 模式三及模式四狀態示意圖.......................................................112
圖5.25  EDFA之埠1、埠2光頻譜圖.......................................................113
圖5.26 可逆式光放大器實驗設置圖(a)正向放大狀態
(b)反向放大狀態..........................................................................114
圖5.27 可逆式光放大器的增益範圍.......................................................115
圖5.28 在不同波長輸入下可逆式放大器的增益特性及雜訊指數
(a)正向放大狀態(b)反向放大狀態..............................................116
圖5.29 可逆式光放大器動態切換實驗設置1.........................................117
圖5.30 實驗設置1之頻譜圖(a)角度1(b)角度2......................................117
圖5.31 可逆式光放大器動態切換實驗設置2.........................................118
圖5.32 實驗設置2之正反放大頻譜圖....................................................118
圖5.33 實驗設置2動態切換結果(a)角度1(b)角度2..............................119
圖5.34 正向光放大器於光纖網路中，OTDR監測線路實驗設置圖....119
圖5.35 濾波器光頻譜...............................................................................120
圖5.36 正向光放大器於光纖網路中，OTDR軌跡圖..............................121
圖5.37 反向光放大器於光纖網路中，OTDR監測線路實驗設置圖......121
圖5.38 反向光放大器於光纖網路中，OTDR軌跡圖..............................122
圖5.39 正/反向光放大器於光纖網路中，OTDR軌跡圖的比較.............122
圖5.40 正常模式下模擬設置圖...............................................................124
圖5.41 光通道頻率配置圖.......................................................................124
圖5.42 保護模式1各項訊號傳輸示意圖................................................126
圖5.43 模擬斷點位置距離ONU 1km時，ONU接收到的光頻譜圖......126
圖5.44 斷點位置對下傳訊號眼圖的影響，斷點位置距離ONU (a) 1km處(b) 10km處(c) 20km處(d)在ONU內設置B/R filter.............127
圖5.45 未設置B/R filter斷點位置對下傳訊號的影響與ONU內設置
B/R filter時BER曲線的比較.......................................................127
圖5.46 在OLT端Red band濾波器濾波之前的光頻譜圖(a)在OLT接收端並未設置光放大器(b)在OLT接收端設置光放大器..............128
圖5.47 在OLT接收端並未設置光放大器時，OLT接收到的眼圖.........129
圖5.48在OLT接收端設置光放大器時，OLT接收到的眼圖(a)未設置
Red band濾波器(b)設置Red band濾波器..................................129
圖5.49 保護模式2之訊號眼圖(a)下傳訊號(b)上傳訊號.......................130
圖5.50 正常模式下ONU1接收到的下傳訊號(a)光頻譜圖(b)眼圖…...130
圖5.51 正常模式OLT端接收到的上傳訊號(a)光頻譜圖(b)眼圖..........131
圖5.52 上/下傳BER曲線的比較 (a)上傳訊號 (b)下傳訊號................132


 
表目錄
表2.1 光隔離器特性規格...........................................................................22
表2.2 不同組態下光衰減量表...................................................................24
表3.1 軟磁材料之種類及用途...................................................................39
表3.2 為圖3.7光方向性量測.....................................................................45
表3.3 半硬磁材料特性表...........................................................................46
表3.4 切換循環方向條件表.......................................................................51
表3.5 各類不同光開關技術的比較表.......................................................58
表4.1 摻鉺光纖放大器之pump組態.........................................................69
表4.2 各種保護方案比較表.......................................................................89
表5.1 不同尺吋電磁吸鐵的規格表...........................................................91
表5.2 VOA完整規格表...............................................................................98
表5.3 正向循環狀態及反向循環狀態的特性.........................................105
表5.4 模式一及模式二量測結果.............................................................111
表5.5 模式三及模式四量測結果.............................................................112
表5.6 雙向EDFA規格表..........................................................................113

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