半導體雷射激發掺銣釩酸鎦雷射之聲光調變主動式Q開關鎖模雷射

Abstract

在腔內沒有額外鎖模元件的情況下，Q開關鎖模雷射已在由聲光調變器所調變的Q開關掺銣釩酸鎦雷射中被觀察到。在我們的實驗中證實，如果要達到掺銣釩酸鎦晶體的Q開關鎖模雷射，並不需要使聲光調變器的射頻頻率與雷射共振腔腔長倒數穩合，並且鎖模調變深度會隨著浦磊強度增強而增加。我們能得到最大至百分之一百的調變深度。這個現象可以用在雷射增益介質上所產生的光學克爾透鏡現象來解釋。同時，我們也得到了最佳的聲光調變頻率與雷射增益介質的螢光生命時間之間的關係。 除此之外，我們也藉由改變不同的共振腔長度，不同的腔內位置以及不同的聲光調變器的調變射頻和不同的浦磊強度，來更進一步的探討輸出功率與它們之間的關係。

Q-switched mode locking (QML) has been observed in acousto-optic Q-switched Nd:LuVO4 laser that contained no mode-locking components. In our experiment proved that the match of acousto-optic modulator’s radio frequency (AOM RF) and invers cavity length is not a necessary criterion to achieve QML with c-cut Nd:LuVO4 and the modulation depth was observed to increase with increased pumping power. The maximum modulation depth was as high as 100%. This phenomenon is explained by the introduction of optical Kerr-lens effect in the gain medium. A relation between optimal AOM RF and fluorescent lifetime of gain medium was also obtained in our experiments. Furthermore, we also discussed the output power by using different cavity length, different position inside the cavity, AOM RF, and pumping power to further investigate their relationship.