高斯光束非球面整形系统整形特性研究

Research on shaping characteristics of Gaussian beam aspheric shaping system

使用非球面透镜对高斯光束整形的方法已经非常成熟,可以根据入射光参数设计出特定的非球面整形镜。但在使用入射光束束腰以3 mm设计的非球面整形镜时发现,非球面整形镜不只适用于设计时的入射参数,在入射光束直径和发散角不同时,整形镜后均会有一个平顶分布最佳的整形位置,该位置随着入射光束直径的增大而远离整形镜,随着发散角的增大而靠近整形镜。为了探究最佳整形位置上整形结果的差异,利用控制变量法进行实验,发现入射光束直径和发散角对该位置上平顶分布的平坦因子没有明显变化,但是光束均匀性和边缘陡度会有最佳值,存在最佳入射参数。为了得到最佳整形位置与入射光束直径和发散角的关系,利用响应曲面法成功建立数学模型,当已知某入射位置处的光束直径和发散角时,可以快速得到最佳整形位置。

The method of Gaussian beam shaping using an aspheric lens has been very mature,and specific aspheric shaping mirrors can be designed according to the incident light parameters.However,when the aspheric shaping mirror designed with a 3 mm incident beam waist is tested,it is found that the aspheric shaping mirror is not only applicable to the incident parameters in the design.When the incident beam size and divergence angle are different,there will be an optimal shaping position with flat top distribution behind the shaping mirror.The position is far away from the shaping mirror with the increase of the diameter of the incident beam,and close to the shaping mirror with the increase of the divergence angle.In order to explore the difference in shaping results on the optimal shaping position,the control variable method is used to carry out the experiment.It is found that the diameter and divergence angle of the incident light beam have no obvious change in the flat factor of the flat top distribution on the position,but the beam uniformity and edge steepness will have the best value,and there is an optimal incident parameter.In order to obtain the relationship between the optimal shaping position and the incident beam diameter and divergence angle,a mathematical model is successfully established by using the response surface method.When the beam diameter and divergence angle at an incident position are known,the optimal shaping position can be quickly obtained.