本論文之主要研究目標為製作模態適配器以改善模態場不匹配所導致的能量損失，進而提升雷射架構的輸出效率。文中所探討的模態場不匹配光纖為10/125-08 SCF與20/125-08 SCF，兩光纖未經過改良前的穿透率大約落在70%左右，本文使用載氫光纖的技術將較小模態直徑的10/125-08 SCF內部填充載氫後搭配熱擴張纖核法，以電弧放電的方式對光纖進行逐次加熱，穿透率最高可提升至90.02%，且由於載氫提高了纖核內摻雜離子的擴散係數，與未使用載氫光纖進行實驗的結果相比約可縮短一半的加熱時間。文中由實驗數據估算出載氫光纖的擴散係數約為一般光纖的2.2倍。將製作的模態適配器實際放入雷射架構進行量測，雷射輸出能量約可提高25%，成功驗證了以載氫光纖結合熱擴張纖核法製作模態適配器的可行性。

The main purpose of this study is to improve the efficiency of the mode-field adapter between two mismatched fibers. The mode- field mismatched fibers discussed in this article are 10/125-08 SCF and 20/125-08 SCF. The transmission of two fibers before improvement is about 70%. By using the hydrogen-loading with a relatively smaller core and arc-induced thermally diffused expanded core method, the transmission can be increased to 90.02%. Due to the hydrogen loading, the diffusion coefficient of the dopants that define the core geometry is enhanced. The arc time can be shortened by about half compared with the result of the experiment without using the hydrogen-loaded fiber. It is estimated from the experimental data that the diffusion coefficient of the hydrogen-loaded fiber is about 2.2 times than that of the general optical fiber. When the produced modal adapter is actually put into a laser structure, the laser output energy can be increased by about 25%, which successfully verifies the feasibility of using this method to make a modal adapter.

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