本論文介紹環型摻鉺光纖雷射，對摻鉺光纖雷射的原理，以及布拉格光纖光柵的製作與應用。
在環型摻鉺光纖雷射的介紹分成三個部分。首先是環型雷射其又可分為前向泵激與後向泵激兩種，我們先使用模擬軟體Optisystem 6.0簡介環型摻鉺光纖的動作原理，並利用圖示深入了解其內容。
第二部分則改由實際的光學元件得來結果，包含使用不同長度的摻鉺光纖、不同波長的布拉格光纖光柵，可以得到環型架構之最佳結果為使用摻鉺光纖7m、光柵波長1597nm、臨界功率8.34mW、斜線效率11.9%。無論前向或後向泵激架構，皆以1597nm波長輸出之效果較好。
第三部分，我們從動作原理了解環型摻鉺光纖雷射在能源上有一定之浪費，由之前實驗中可得到由泵激光源與自發性輻射兩方面改善，設計出泵激光源的回收使用，以及自發性放大輻射之回收使用。前者藉由寬頻譜反射鏡將殘餘泵激光源導回摻鉺光纖，此種改善在泵激光源100mW可提升輸出功率0.9dB、斜線效率2.66%；後者我們設計將摻鉺光纖分為兩段使用，此種改善在相同的泵激光源下可提升輸出功率2.8dB、斜線效率5.89%。
最後，再將線性型與環型兩種架構做比較，包含雷射輸出的功率、斜線效率及應用性。由比較的結果發現，線性型雷射的輸出特性較佳；而環型的應用性則有較好的表現。

In the thesis, we studied and investigated ring-cavity erbium-doped fiber laser (EDFL). In the beginning, we introduced the theories of both EDFL and tunable fiber Bragg grating (FBG). Then the simulation software Optisystem 6.0 was used to calculate the characteristics of ring-cavity EDFL. To confirm the calculated results, several experiments were conducted by varying the parameters of fiber components. The vary parameters including erbium doped fiber (EDFs) length, FBG wavelength and FBG reflectivity. In both forward and backward pump schemes, 1597 nm have better performance than those of 1581 nm under 100 mW pump power. At 1597 nm, we found that 7-m EDF and 100% reflectivity of FBG may result in threshold power, output power, slope efficiency and signal to noise ratio (SNR) of 8.34 mW, 10.96 dBm, 11.9 % and 66.66 dB, respectively. Although longer EDF such as 10- or 12 m may lead to lower output power when compares to 7 m ring-cavity EDFL, the problem could be solved by recycling the residual pump power using a broadband fiber mirror and/or separating the EDF into two sections. Under 100 mW pump power, the laser output power and slope efficiency are 0.9 dB and 2.66% improved for the first case. On the other hand, the laser output power and slope efficiency are 2.8 dB and 5.89% improved for the second case, respectively. We compared several measured characteristics between ring-cavity EDFL and previous studies of linear-cavity EDFL in our laboratory. Under the same pump power, the linear-cavity EDFL has larger output power and slope efficiency than those of ring-cavity EDFL. On the other hand, the ring-cavity EDFL has better SNR and performance when acts as a fiber sensor source, as compared to those of linear-cavity EDFL.

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