用于激光加工中的矩形孔径Dammann光栅光束变换技术

针对大功率激光加工对光束空间强度分布的实际要求,提出了一种用二元光学元件对光束进行变换的方法,即利用均匀采样的矩形孔径Dammann光栅对激光高斯光束进行光束变换,可满足任意点阵分布的输出要求.以线状、均匀、环状和非均匀分布的光强输出为例,介绍了矩形孔径Dammann光栅光束变换技术的设计原理及实现方法,结果表明输出光强分布具有较高的衍射效率和均匀性.将均匀和非均匀分布的输出光束应用在激光加工技术的表面强化上,结果表明试样表面的硬度和耐磨性等力学性能均有提高并且强化层具有较好的均匀性.

Beam Transformation Technology of Pixellated Dammann Grating in Laser Processing

A kind of binary optical elements is introduced to implement the transformation of laser beam for high power laser processing.The even sampling Pixellated Dammann grating is adopted to perform the Guassian beam transformation in order to obtain the given output spots.The principle and implementation of the beam transformation technology of pixellated Dammann grating is described with examples of the linear,even,annulus and uneven array.Results show that the output spots have high diffractive efficiency and uniformity.The application of the even and uneven array spot in the laser surface modification is investigated,showing the improvement of the hardness and the wear resistance of the sample surface,and the uniformity of the modified surface.