实现Nd:YAG光束匀滑的衍射光学器件的研制

Design, fabrication and experiment of diffractive optical element to realize Nd:YAG laser beam smoothing

采用爬山 -模拟退火混合优化算法与旋转镂空掩模板工艺 ,针对基频光与三倍频光 ,设计并加工出口径 80 mm的连续位相衍射光学器件。在脉冲工作的 Nd:YAG激光器上 ,实验研究了器件的光束匀滑性能 ,获得了与设计尺寸相符合、边缘陡峭、但包含较大顶部调制的光斑。

The hybrid algorithm, combing hill-climbing and simulated annealing, and hollowed-out mask are adopted to design and fabricate the diffractive optical element (DOE) with diameter 80 mm, to realize beam smoothing for the fundamental wave and the third harmonic wave of Nd:YAG laser. The edge of the DOE is measured by the profilometer, which shows a rather large etching depth error exists. The performance of the DOE is experimentally studied with a pulse-operating Nd:YAG Laser. Focused spots have been obtained with the corresponding design size and sharp edge, while a large top modulation exists too. The feasibility of the DOE used in the solid laser beam smoothing is preliminary proved by these firstly obtained experimental results.