本論文研究被動Q-開關Nd：YVO4雷射的非線性動態行為。隨著外加調制訊號的頻率上升，脈衝序列所表現的行為依序會出現：週期二、週期三、週期一、最後出現混亂分佈的動力學現象，有著某種路徑發展的行為，並且同時發現訊號頻率接近系統脈衝重複頻率附近時，脈衝序列抖動程度會變得非常穩定，另外此週期一之脈衝寬度與未調制比較後相對的壓縮。模擬以弦波調制泵源訊號當主軸，模擬結果的脈衝序列所有動力學現象與實驗符合。分析某些脈衝得到更強激發而使本身峰值強度更強，而某些脈衝卻因獲得不多的激發而變得更弱，所以導致形成了週期二訊號，同理週期三訊號。因此我們可知，被動式Q開關在外加訊號源的情況下可對系統產生控制或某種抑制的行為。

n this thesis, we study that the nonlinear dynamical behavior in passively Q-switched Nd:YVO4 laser. With increasing the modulation frequency of pumping source, the behavior of the pulse train in sequence will occur: period two, period three, period one and finally chaotic dynamics phenomena with some path of development. At the same time when the modulation frequency was closed to the pulse repetition frequency, the timing jitter of pulse train became very stable, and the pulse width compared with pulse train without modulation was compressed. In simulation, we modulated gain with sine wave. All the dynamic behavior of the pulse train of simulation corresponded with experiment. It’s easy to analyze that some pulses of the pulse train have stronger excitation and become the stronger peak intensity, and some pulses become weaker one because of small excitation. This phenomena lead to be period two signal. So does the period three, and so dose chaotic pulse train. The Q-switched pulse laser system can be controlled into special condition by gain-modulation with some special frequency.

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