Generating high uniformity Bessel beam is an interesting target in laser processing. An axicon with a high-order curved surface is proposed to generate Gaussian–Bessel beams with high uniformity and high energy utilization. The original phase function of the standard axicon is replaced by multiple polynomials, which are optimized by a combined algorithm employing the genetic algorithm and the unconstrained nonlinear minimization algorithm. Simulation and experiment results demonstrate that the combined algorithm not only significantly reduces the time complexity of the algorithm greatly but also achieves high uniform intensity distribution at the focal segment. By compensating and optimizing the fifth-order surface axicon, the energy utilization is 17.734%, and the uniformity can reach 93.86%. The processing experiment results confirmed that the presented method can extend the processing depth and obtain high quality.

中文翻译：

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高阶曲面轴棱镜产生的高均匀性贝塞尔光束

产生高均匀性贝塞尔光束是激光加工中一个有趣的目标。提出了一种具有高阶曲面的轴锥镜来产生具有高均匀性和高能量利用率的高斯-贝塞尔光束。用多个多项式代替标准轴锥镜的原始相位函数，并采用遗传算法和无约束非线性最小化算法的组合算法对其进行优化。仿真和实验结果表明，该组合算法不仅大大降低了算法的时间复杂度，而且在焦点区域实现了高度均匀的强度分布。通过对五阶面轴锥镜进行补偿优化，能量利用率为17.734%，均匀度可达93.86%。