本篇論文採用全光纖雷射架構，使用915nm的Laser Diode作為Pump Source，將能量耦合進入Double Cladding Fiber(DCF)轉變成Cladding Pump System，Gain Medium為摻鐿光纖，產生976nm三階CW雷射。
製作過程中為了避免模態競爭的問題，將摻鐿光纖的長度設定於15cm以下，但因為是採用Cladding Pump System，而鐿離子只在光纖的Core中摻雜，所以長度固定後就導致摻鐿光纖對Pump Source的吸收效率降低。因此我們藉由氫氟酸蝕刻，將光纖的Cladding Diameter蝕刻至近40um，提升摻鐿光纖對Pump Source的吸收效率，但蝕刻後的摻鐿光纖因表面被破壞而導致穿透率不佳，因此我們透過CO2雷射退火修復光纖表面，以提升蝕刻後光纖的雷射效率。
我們首先蝕刻並退火光纖SMF130V，談討CO2雷射退火對其的影響。將SMF130V蝕刻至約40um後退火，使得原來穿透率僅為29.3%的光纖改善至74.2%，穿透率變化4.03dB，並用SEM明顯的觀察到了光纖表面被修復。
瞭解CO2雷射退火的效益後，我們將摻鐿光纖蝕刻至約40um並量測976nm雷射功率。摻鐿光纖退火前雷射門檻高於6.5W；退火後雷射門檻降低至2W，雷射輸出功率218mW，成功降低了976nm三階雷射的門檻並提升了其雷射效率。

This thesis is an all-fiber laser system using the cladding pump technique. We take a 915 nm laser diode as the pump source and ytterbium-doped fiber as the gain medium to generate a three-level ytterbium-doped fiber laser at 976 nm.
Considering the mode competition, we design a length of ytterbium fiber below 15 cm, and it brings about poor absorption of the ytterbium-doped fiber to the pump source. Therefore, we use the etching fiber method using hydrofluoric acid. The cladding diameter of the ytterbium-doped fiber is etched to approximately 40 um and improves the absorption efficiency. However, the surface of the ytterbium-doped fiber is damaged after the etching process and results in poor transmission. We repair the surface of the etched fiber through CO2 laser annealing to improve laser efficiency.
We start by etching the single-mode fiber (SMF130V) to research the CO2 laser annealing effect on the fiber. We use the CO2 laser to anneal the surface after the SMF130V cladding is etched to 40 um, approximately. The transmission of fiber is improved from 29.3% to 74.2% and changed in 4.03 dB after annealing. We also find out that the SMF130V surface is repaired apparently by SEM.
Then we etch the ytterbium-doped fiber to approximately 40 um and measure the power of the laser at 976 nm. The results show that the threshold pump power of the laser at 976 nm is declined to 2W, and the power of the laser is 218 mW after annealing, as compared to the threshold pump power, which was higher than 6.5 W before annealing. We decrease the pump threshold of the laser at 976 nm and improve laser efficiency successfully through CO2 laser annealing on the cladding diameter of the ytterbium-doped fiber, which is only about 40 um.

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