本論文研究含摻鉻釔鋁石榴石飽和吸收體的摻釹釩酸釔雷射在平凹共振腔中的被動Q-開關。在實驗上我們證實在以摻釹釩酸釔晶體的一端為平面鏡的平凹共振腔中無法利用摻鉻釔鋁石榴石飽和吸收體來獲得良好的被動Q-開關。然而我們發現若將凹面鏡移至共振腔穩定範圍外則可得到良好的被動Q-開關。實驗中我們探討了Q-開關脈衝寬度，重複頻率，平均功率與泵浦功率，凹面鏡反射率和曲率半徑等參數之間的關係。在846mW的泵浦功率，凹面鏡的反射率為90%，曲率半徑為25.4mm的條件下，獲得了脈衝寬度4.9ns，重複頻率8.6kHz，平均功率7.6mW，單一脈衝能量0.9μj，峰值功率185W的Q-開關脈衝。就我們所知，此為迄今在摻釹釩酸釔雷射晶體暨摻鉻釔鋁石榴石飽和吸收體系統中所獲得最短的Q-開關脈衝。 In this thesis, we investigate the passive Q-switching of diode-pumped Nd:YVO4 laser with Cr+4:YAG saturable absorber in a plano-concave cavity. We find that a good passive Q-switching effect can not be obtained in this system except for moving the concave mirror beyond stable region of the cavity. In addition, we study the relationship of the pulse width, repetition rate, and average power as a function of pump power as well as reflection coefficient and radius of curvature of the concave mirror. Stable Q-switched pulses as short as 4.9 ns with repetition rate of 8.6 kHz and average power of 7.6mW corresponding to pulse energy of 0.9μj and peak power up to 185W are generated. This is to our knowledge the shortest pulse width being achieved in the passively Q-switched Nd:YVO4 laser by using Cr+4:YAG as saturable absorber.
