摻鐿釔鋁石榴石自鎖模雷射

Abstract

高重複率的脈衝雷射在工業、通訊與學術研究方面均有很廣泛的應用，因此本論文使用Yb:YAG當作增益介質，搭配自鎖模方法來創造高重複率的脈衝雷射。我們利用不同摻雜濃度的Yb:YAG以及不同的共振腔設計來研究自鎖模雷射其輸出表現，在實驗中發現其脈衝重複率可以達到600GHz，這是由於增益介質表面有鍍膜，會形成『標準具效應』來達成諧波鎖模。實驗中使用鑽石散熱片來減少熱效應以提昇雷射功率。另外我們也在實驗中觀察到在不同時間尺度下，雷射總共會有四層不同的波動變化，最外層及第三層波動為偏振態競爭所造成，第二層波動為張弛振盪，而最內層波動為鎖模脈衝。

Pulsed lasers with higher repetition rates have extensive application in industry, communication, academic research. In this thesis, we use Yb:YAG as a gain medium with self-mode-locked method to create a high repetition rate pulsed laser. We use different doping concentrations of Yb:YAG and different cavity design to study the performance of self-mode-locked laser output. In the experiment, the pulse repetition rate up to 600GHz. The gain medium is coated to form a cavity mirror and to play an etalon for achieving harmonic mode-locking. A diamond heat spreader is employed to reduce the thermal effects for power scale-up. In addition, we also observed in the experiment, the Yb:YAG self-mode-locked laser will have four layers fluctuations under different time scales. The outermost and the third layer caused by the polarization competition, the second layer for relaxation oscillation, while the innermost layer of the mode-locked pulse.