LD抽运腔内倍频456nm激光阈值理论分析与实验研究

Threshold theory analysis and experimental research of LD pumped intracavity-frequency-doubled 456nm laser

从准三能级激光系统阈值理论出发,分析了影响激光阈值的几个因素。实验中采用标称输出功率为3W的LD,端面抽运掺杂浓度为0.15atm.%Nd:GdV04晶体,利用曲率半径为30mm的输出镜,使用LBO晶体I类相位匹配倍频获得了阈值大约为0.42mW的456nm蓝色激光输出。在抽运功率为1.9W时,最高功率达82mW,光-光转换效率为4.32%。为具体比较晶体掺杂浓度、输出镜曲率半径对激光阈值产生的影响,又采用尺寸相同,掺杂浓度为0.25atm.%的晶体以及曲率半径为50mm的输出镜进行了对比实验分析。结果表明,较低掺杂浓度晶体和较小曲率半径输出镜的激光阈值较低。

Some factors which affect laser threshold were analyzed in the quasi- three- level laser system theory. A 3W LD, a Nd： GdVO4 laser crystal of 0.15atm. % doped concentration, and a output coupler with radius of 30mm, were chosen in this experiment, and 456nm laser threshold was realized at 0.42W. Whenthe input pump power was 1.9W, the , maximum continuous 456ran laser of 82mW was achieved, and the optical - to - optical conversion efficiency amounted to 4.32 %. To concretely analysis the effect of laser crystal doped concentration and output coupler radius on the laser threshold, another Nd ： GdVO4 laser crystal of the same size, with 0.25arm. % doped concentration and another output coupler with radius of 50mm were used to take some contrastive experiments. As a result, the laser threshold was smaller at the lower doped concentration crystal and smaller radius output coupler.