高功率绿光激光器热稳定性的研究

The study of thermal stability on a laser-diode-pumped high-power green laser

本文报道了对平均功率达110W的高功率、高重复频率全固态绿光激光器热稳定性的研究。针对实验中出现的532nm绿光输出平均功率不稳定的情况,分析了泵浦电流、谐振腔长度等因素的变化对平-凹腔的稳区范围和腔内激光模式特性的影响。理论分析中分别把KTP晶体和Nd:YAG棒看做薄透镜和热透镜,通过计算谐振腔传输矩阵的方法,得到了稳区范围和腔内光束分布情况。实验中采用的泵浦头由80个20W的高效率半导体激光器组成,按照五角形等间距侧面泵浦Nd:YAG棒,采用高效率的声光Q开关,倍频晶体为Ⅱ类相位匹配的KTP晶体(φ=24.7°,θ=90°),最终得到了平均功率为110W的532nm激光输出,实验结果与理论计算符合得很好。

In this paper, research on the thermal stability on a laser - diode - pumped high - power high - repetition - rate intracavity frequency doubled 532nm laser was reported. In the experiment, we found that the average output power of 532nm fluctuated with the variety of pumping current and the length of the resonator,we consider the KTP crystal as a thin lens and look the Nd：YAG rod as a thermal lens respectively,by ray matrix methods,we have obtained the stable regions and analysed the characteristie of the laser modes in the fiat - concave cavity. In our experiment,we used a pump head consisting of 80 diode bars（20W output power） with pentagon pump model,using an acousto- optic Q- switching with hgh efficiency,the KTP crystal which was type Ⅱ phase matehing（φ = 24.7 °, θ = 90°）, 110W high stability 532nm laser was achieved. The experimental result is in good agreement with the calculation.