利用Nd:YAG/Cr4+:YAG擴散鍵結晶體實現能量可調式微型被動式Q開關雷射

Abstract

為實現微型能量可調的被動式Q開關雷射的概念，本實驗使用半導體雷射作為激發光源，激發帶有切角的Nd:YAG/Cr4+:YAG键合晶體，透過改變橫向激發位置調整初始穿透率的方式，實現輸出光能量可調整的目的。使用不同長度的晶體以及改變激發面積的實驗結果也在此論文中闡述。另外，我們亦以改變輸入功率和激發光位置的方式，保留基態橫模的輸出以維持良好的光束品質。應用方面，我們以本實驗架構所激發出來的近紅外光作為基頻光，加以倍頻處理後產生可見的綠光，並將整組實驗架構加以模組化，以期能運用在實際的產業需求。

To demonstrate an energy adjustable passively Q-switched laser, a diode laser pumped Nd:YAG crystal diffusion-boned with a wedged Cr4+:YAG crystal is utilized. By changing the transverse pump location of the laser diode on the laser crystal, the initial transmission of the saturable absorber can be flexibly adjusted to achieve the variation of output pulse energy. The experimental result for different crystal length and different pump area are also shown in the thesis. In addition, the multi-transverse-mode output is eliminated to maintain good beam quality by controlling the input power and pump location. For further applications, the 1064-nm PQS laser is utilized to generate a frequency-double 532-nm laser. Finally, the whole set of the green laser is modular in order to be used in actual industrial demand.