長波段摻鉺光纖放大器近來受到高度的重視，新增1570 ~ 1600 nm長波段的放大範圍若與傳統波段（1530 ~ 1560 nm）的摻鉺光纖放大器並行使用，便能增加波長分波多工系統的傳輸容量達一倍以上。在系統中，當訊號功率或頻道數不停的發生變動時，一般增益平坦化的靜態控制技術便無法有效控制各個頻道的功率為固定值。因此，動態增益控制技術便發展出來。而增益控制的研究目前仍限於傳統波段的摻鉺光纖放大器，在長波段摻鉺光纖放大器的方面，尚未見任何報導。本研究的目的是發展長波段摻鉺光纖放大器增益控制的方法，觀察其增益和雜訊指數。
在不同的回授信號波長（1568 nm和1600 nm）和衰減量對於長波段摻鉺光纖放大器增益控制的結果不同，而由實驗結果發現不論單波長或多波長傳輸時，若將回授信號lGC=1568 nm和lGC=1600 nm比較後，則以回授信號lGC=1568 nm對於長波段摻鉺光纖放大器增益控制的效果較佳，其中以衰減量ATT＝0 dB時，增益的變化量最少（約為0.1 dB），且增益值較高（約為19.4 dB），輸入信號功率的可變動範圍DR≧30 dB。與未加上增益控制技術（W/O GC）時相比，增益變化量改善17 dB，輸入信號功率的可變動範圍改善25 dB。

Recently, the long-wavelength band (L-band, 1570-1600 nm) erbium-doped fiber amplifiers (EDFAs) has received much attention. By combining the gain bandwidth of a conventional C-band EDFA and L-band EDFA in parallel, the available gain bandwidth can be increased by a factor of two. The change in the input power and the number of channels leads to the variation of the channel output power, which, in turn, changes the gain spectrum and flatness. To cope with this problem, the gain-clamped (GC) technique has been proposed. The gain-clamping techniques have been extensively explored for C-band EDFAs, but fewer for L-band EDFAs.
In this thesis, we experimentally investigate an optically gain-clamped L-band EDFA with different lasing lights (1568 nm and 1600 nm) and different loop attenuation. The characteristics of such L-band GC-EDFAs measured in a simulated add-drop operation are examined and compared. We find that the 1568-nm lasing light with 0-dB loop attenuation is the better selection for L-band GC-EDFA to offer good channel gain (19.4 dB) and satisfied noise figure characteristics. Compared to the gain variation observed for GC-EDFA with an open loop, the GC-EDFA was effective in reducing the total gain variation of 17 dB and increasing the dynamic range of 25 dB.

中文摘要………………………………………………………………Ⅰ
英文摘要………………………………………………………………Ⅱ
內容目錄………………………………………………………………Ⅲ
附表目錄………………………………………………………………Ⅳ
附圖目錄………………………………………………………………Ⅴ
第一章 簡介…………………………………………………………1
1.1 研究背景…………………………………………………………1
1.2 研究動機…………………………………………………………2
1.3 論文結構…………………………………………………………2
第二章 摻鉺光纖放大器增益控制技術之原理與特性……………3
2.1 摻鉺光纖放大器之基本原理……………………………………3
2.2 光放大器特性參數的定義與量測方法…………………………6
2.3 增益控制技術之原理……………………………………………10
2.4 傳統波段摻鉺光纖放大器增益控制技術之介紹………………11
2.5 長波段摻鉺光纖放大器與增益控制技術………………………15
第三章 長波段摻鉺光纖放大器增益控制技術之實驗……………17
3.1 元件特性量測及光放大器之組裝………………………………17
3.2 長波段摻鉺光纖放大器增益控制技術之組……………………19
3.3 單一波長特性量測結果…………………………………………20
3.4 多波長特性量測結果……………………………………………22
3.5 討論………………………………………………………………23
第四章 結論…………………………………………………………25
參考文獻………………………………………………………………26
附表……………………………………………………………………28
附圖……………………………………………………………………31

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