大功率激光扩束器的光学设计

The optical design of high-power laser-beam expander

为了使激光扩束器可以长时间的工作于大功率激光照射情况下,在传统多波长激光扩束器的基础上,利用变更材料和结构的方法进行改进,设计了2.3倍和6倍两级扩束的激光扩束器,用光学设计软件分析其像质并进行优化,对像质进行理论分析;加工成型后,置于实际环境中进行实验。经实验验证,在调Q脉冲激光器的峰值功率高达20MW的大功率激光照射下,在系统后1m位置出射光束直径分别为24.5mm和154.8mm,脉冲间隔可以在5s以上,并很好地保持了高斯光束的固有特性。结果表明,扩束器完全达到设计要求,有良好的使用效果。

In order to make a laser beam expander work a long time under high power laser radiation, on the base of the traditional multi-wavelength laser-beam expander, a two-serial expander with magnification of 2.3 and 6 respectively was designed through modifying the optical material and configuration. The expander was optimized and its image quality was analyzed with optical design software. After the expander was manufactured, experiments were performed in practical environment. It could work for a long time under laser radiation with pulse interval of 5s at high peak power up to 20MW, the output beam diameters were 24.5ram and 154.8mm respectively at 1 m behind the expender with the characteristic of Gaussian-beam kept very well. The result indicates that the expender meets the design requirement and is practical.