焦斑可调的透镜阵列均匀辐照光学系统

Improved Lens Arrays Optical System with Controllable Focus Width for Uniform Irradiation

提出用两组透镜阵列与非球面透镜组成焦斑可调的均匀辐照光学系统,可实现靶面光斑尺寸在几微米到几毫米的范围内连续可调,并且能将圆形入射激光束变换为方形均匀焦斑,同时满足二维激光光束形状的改变和强度空间分布均匀化的要求。应用矩阵光学、衍射积分理论,详细分析了它的工作原理,给出了系统优化设计参数和详细的数值计算结果。模拟计算结果表明,当靶面离焦量为Δz=2 mm时,x,y方向平顶区的不均匀度分别为η_x =4．6％,η_y=5．3％,能量利用率达到95．3％,基本上达到了设计要求。Zemax光学设计软件的仿真实验测试结果与理论分析结果吻合得很好。

A novel lens arrays optical system with continuously variable focus width from several microns to several millimeters for providing uniform irradiation is proposed, which is composed of two lens arrays and an aspherical lens, and the system converts a circular laser beam into a flat-top square focused spot, which realizes the transformation of beam-shape and the uniform distribution of the spatial intensity at the same time. Based on the adaxial matrix optics and scalar quantity diffraction integral theory, the principle of this system is analyzed, and optimum design of the system parameters and numerical calculations for this system are presented in detail. The simulated results show that the nonuniformity along the x and y direction are η x= 4.60%,η y = 5.3 % respectively, the energy efficiency can be up to 95.3%, and by moving the target slightly backward from the focal plane, offfocus length △z = 2 mm is obained, which nearly satisfies the need. The theoretical analysis agrees with the results of the emulational experiment with Zemax optical design software.