臺灣博碩士論文加值系統

被動式Q開關固態雷射廣泛地應用在近代科學、醫學、工業界中，例如半導體元件量測、醫美手術、眼科雷射、微精密加工等。Q開關雷射雖可產生高功率的短脈衝，但伴隨鎖模使其峰值功率波動較大，提升峰值功率的穩定性與更精準地控制雷射系統為本論文目標，因此在不改變原共振腔的情況下，利用腔外回授鏡形成耦合共振腔去改變雷射狀態形成破壞性及增益性的鎖模，並有效控制鎖模深度進而調製出比原始雷射更穩定的無鎖模與增益性鎖模現象。開發一系列自動化軟體應用於雷射系統中，取代過去人工進行實驗，有效提升實驗效率並降低人為誤差及排除不穩定因子，透過自動化改變腔外回授鏡距離、角度，研究鎖模的脈衝波形、雷射能量、峰值功率間變化趨勢的關聯，定義出比以往更精準的破壞鎖模之區間和參數，為日後雷射系統結合人工智慧落實自動搜尋雷射最佳點來鋪路。

In modern science, medicine, and industry, passively Q-switched (PQS) lasers have been widely applied, such as measurement of semiconductor components, cosmetic surgery, ophthalmic lasers, and micro-precision machining. Although PQS lasers can generate short pulses with high power , the peak power fluctuates greatly with mode-locking. Therefore, improving the stability of peak power and controlling the laser system more accurately are the goals of this thesis. Without changing the original cavity, the external feedback mirror placed after laser output coupler is used to form the coupled cavity to modulate the laser states to generate destructive and constructive mode locking. Moreover, we successfully controlled the depth of mode locking to modulate a constructive mode-locking phenomenon which was more stable than the original laser, and a purely Q-switching phenomenon. In order to replace the manual experiments in the past, we have developed a series of automatic software applied in the laser system, which can effectively improve the experimental efficiency, reduce human errors and eliminate unstable factors. By automatically manipulating the distance and angle of the external feedback mirror, we studied the relationship between the mode-locking pulse shape, energy, and peak power. We successfully defined the intervals and parameters for destructive mode locking more precisely than ever. In the future, it will pave the way for laser system to combine artificial intelligence to automatically search for the best point of the laser.

中文摘要 i
Abstract ii
目錄 iii
圖表目錄 v
一、緒論 1
1.1 研究動機 1
1.2 論文架構 2
二、原理及研究方法 3
2.1 Nd:YAG晶體介紹 3
2.2 雷射原理 7
2.3 Q開關雷射機制 9
2.4 鎖模雷射 13
2.4.1 主動鎖模雷射 (Active mode-locking) 17
2.4.2 被動式鎖模雷射 (Passive mode-locking) 17
2.4.3 自發性鎖模雷射 (Spontaneous mode-locking) 18
三、實驗器材設備與方法 20
3.1 實驗器材設備 20
3.2 實驗方法 27
3.2.1 微調回授鏡角度方法 27
3.2.2 運用MATLAB分析波形鎖模深度 28
四、自動化控制腔外回授鏡於Q開關雷射系統 29
4.1 使用Kinesis於LabVIEW中控制設備 29
4.2 LabVIEW控制Nd:YAG雷射系統 38
4.3 自動記錄能量偵測器之量測值 45
4.4 偕同示波器自動擷取波形 48
五、利用腔外回授鏡控制Q開關雷射的鎖模現象 52
5.1 腔外回授鏡與輸出鏡的距離對Q開關雷射的影響 54
5.2 格柵式掃描與S型掃描之實驗結果 59
5.3 腔外回授鏡距離輸出鏡8公分處之破壞鎖模實驗 77
六、總結與未來工作 85
參考文獻 86

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