超大異常色散被動鎖模掺鉺光纖雷射 之研究

Abstract

在本論文中，我們利用偏振疊加波鎖模原理架設超大異常色散的鎖模光纖雷射，其共振腔長達400公尺，可產生500KHz超低重複率的鎖模脈衝。此雷射隨著調整激發雷射功率強度和偏振控制器角度可產生不同形式之脈衝，在實驗上我們觀察到當激發雷射功率較低時，隨著偏振控制器角度的不同可得到穩定Q開關鎖模脈衝或者是多個光固子的脈衝序列。當激發功率強度上升到一定程度則會得到穩定的鎖模脈衝雷射輸出，這時調整偏振控制器角度可得到不同形狀的脈衝形狀，其中較為特別的為方波輸出。最後透過腔外脈寬壓縮我們可以利用此雷射的超低重複率來產生超高峰值功率的脈衝。

In this thesis, we study the characteristics of a passive mode-locked Er-fiber laser with over 400m single mode fibers inside the cavity to achieve a low pulse repetition rate of 500 kHz. The laser can generate different pulse shapes by adjusting the polarization controllers (PCs) and the pump power, Stable Q-switched mode-locked (QML) pulses or modelocked soliton pulses can be generated after properly rotating the angles of the polarization controllers (PCs) in the low pump power. When the pump power is increased, the mode-locking operation can be observed. Then by adjusting the angles of the polarization controllers different shapes of pulse trains can be generated. Finally, through external pulse compression we utilize this laser to produced high peak power pulse trains with low repetition rates.