在许多测量系统以及激光焊接的系统中，拥有一字线图案的激光器发挥着重要的作用。为了提高传统一字线激光器光学系统的光能利用率和改善光学照明效果，研究设计了一种自由曲面反射镜，使得光线在细线的宽度方向准直出射，在长度方向以大角度扩散，同时也保证照度均匀性。通过建立自由曲面模型、构建偏微分方程，得到自由曲面点云的数值解，从而拟合得到自由曲面面型。仿真结果表明，发散角在高达150°时，照度均匀性高达90%，在不考虑反射率损失时能量利用率在99%以上。

Laser with straight- line light pattern and uniform illumination is required in many measurement systems and laser welding systems. Instead of the traditional methods using diffractive optical elements and cylindrical lens, a free- form surface design method for laser diode source is proposed to improve the utilization efficiency of the light energy and the optical lighting effect, utilizing a free- form reflector to distribute the light uniformly in one direction and collimate the light in the orthogonal direction. Through the establishment of free surface model, constructing the partial differential equation, and solving the point cloud of surface, the shape of the freeform surface is obtained. Compared with the traditional methods in the line pattern design, the efficiency and uniformity are both significantly enhanced by this method. The simulation result shows that an illuminance uniformity is about 90% and an efficiency about 99% (without considering the reflectance loss) are achieved within 150° of the spread angle.