脉冲单频Nd:YVO4激光器及其倍频输出特性研究

为了研制激光干涉成像所需的主振荡功率放大(MOPA)结构脉冲单频激光器,本文完成MOPA激光器的种子源即声光调Q脉冲单频1 064 nm激光器的特性研究,同时完成种子源腔外倍频绿光特性研究。脉冲单频激光器采用声光调Q模块实现脉宽约20 ns的1 064 nm脉冲激光输出,采用环形腔设计并采用一组不同厚度的标准具实现单纵模运转。实验研究基频1 064nm和倍频532 nm激光脉冲的线宽,得出在全脉宽范围内都具有较高时间相干性的结论。实验分别获得脉宽约28 ns峰值功率约6.5 kW的1 064 nm脉冲单频激光和脉宽约20 ns、峰值功率约0.5 kW的532 nm脉冲单频激光,腔外倍频效率为5.6%。实验同时也验证了腔外倍频的激光脉宽压缩效应。

Properties of pulse single-frequency laser and extra-cavity double frequency green laser

In order to manufacture a pulse single-frequency laser with master oscillator power amplifier(MOPA) structure used for laser coherence imaging, the properties of acousto-optic Q-switched pulse single-frequency 1 064 nm laser used as MOPA laser seed, and properties of extra-cavity double frequency green laser were studied in the paer. 1 064 nm pulse laser output with more than 20 ns pulse width was realized by means of acousto-optics Q-switch, and single-frequency running was realized by means of loop cavity and etalons with different thickness. The linewidth of 1 064 nm and 532 nm pulse lasers were studied. The experiment results show that there is almost complete coherence in all of the pulse width;1 064 nm pulse single-frequency laser with 28 nm pulse width and 6.5 kW peak power and 532 nm laser with 20 ns pulse width and 0.5 kW peak power are obtained respectively. The efficiency of extra-cavity double-frequency is about 5.6%. The effect of laser pulse reduction by extra-cavity double-frequency is also validated by experiments.