二极管侧面泵浦薄片激光器泵浦均匀性分析

 建立了二极管侧面泵浦复合薄片激光介质Nd:YAG/YAG的数值模型：二极管阵列的快轴垂直于薄片激光介质表面的排布，二极管对称排列在增益介质的周围，从侧面进行泵浦，通过微柱透镜对二极管的快轴进行准直。模拟并实验研究了激光二极管慢轴方向的远场分布特性，结果发现在近距离时激光二极管慢轴方向上的远场分布近似为高斯分布。对于二极管参量，研究发现泵浦二极管越多，增益介质内泵浦光分布就越理想；增益介质吸收系数越小，泵浦的均匀性就越好，但总的吸收效率下降；二极管与工作物质的距离越近，工作物质靠近中心的区域对泵浦光的吸收就越多，但泵浦的均匀性就越差。选用增益介质为Nd:YAG/YAG的复合薄片介质，当掺杂原子分数以及增益介质的吸收系数不同时，发现0.6%掺杂的增益介质(吸收系数为0.24 cm^-1)的泵浦均匀性比1%掺杂(吸收系数为0.51 mm^-1))有明显改善，实验结果与模拟结果一致。

Pump distribution in LD side-pumped disk laser

A mathematic model of the laser diode array(LDA) side-pump composite crystal Nd:YAG/YAG disk laser is set upLDA fast axis is upright to disk face and micro lens collimate the fast axis. Far-field divergence angle of the slow axis is calculated and simulated，the result showsfar-field divergence angle of the slow axis has approximately Gaussian distribution. Study shows that more diodes lead to better pumping intensity distribution; the least absorption coefficient of laser medium, the best pumping intensity distribution; the smaller distance between diode and laser medium, the worse pumping intensity distribution. The phenomenon can be observed from the experiment with different absorption coefficient of Nd:YAG/YAG ,the pumping intensity distribution becomes better when there is 0.6%