为了得到工业上广泛使用的基模拉盖尔-高斯光束, 2 kW射频板条激光器谐振腔输出的简单像散光束需要腔外光束整形系统, 理论分析和实验研究了变换系统中各光学元件对输出光束光强分布的影响, 取得了在系统中不同光学元件处的光强分布数据。结果表明, 经光束系统后, 输出光束首先由带高频振荡的矩形象散光束聚焦成条状的光束, 然后由空间滤波器滤除非稳光束的高频振荡, 滤除后光束到达柱面镜处非稳与波导方向半径近似相等为5.7 mm, 接着柱面镜将非稳和波导方向光束的发散角转为近似相等, 光束变为非象散光束, 最后再经球面镜准直为近圆形高斯分布光束。所得到的结果对腔外变换系统的进一步优化提供了重要的参考。

The beam shaping system of the 2 kW RF slab CO2 laser composite several optical elements, which turn the output beam into the circular Gaussian beam for industrial applications. The theory and experimental study of the effect of the shaping elements on the characteristic of the output beam for 2 kW RF slab CO2 laser was investigated. First, the rectangular astigmatism output beam with high frequency oscillationwas changed to the strip focused beam, then the high frequency oscillation of the beam was eliminated by through the spatial filter, the width of the beam in the two directions are equal 5.7 mm at the cylindrical lens. The divergence angles of the shaped beam in the two directionsbecome equal, and the shaped beam was changed to non-astigmatic beam after the cylindrical lens.Finally, the circular Gaussian beam was gutted by the spherical lens. The results in this paper are useful for the optimization of the beam shaping system.