Invariant Bessel–Gauss beams have attracted great interest for transparent material microprocessing applications. The small central peak and elongated focal region of the zeroth-order Bessel–Gauss beam provide advantages in laser micromachining. However, many transparent material processing applications need asymmetric beams to induce directional cracking. Therefore, in this work, we investigate analytically, numerically, and experimentally a beam that was generated by spatially displaced axicon halves, which induces noncylindrical symmetry in the beam phase profile. Analytical solutions were found and verified experimentally. High power and quality beams were generated by writing a needed phase alteration of the beam with a geometric phase element. These beams were able to demonstrate applicability to micromachine processing of transparent material.

中文翻译：

---

用于透明材料激光微加工的空间位移和叠加贝塞尔光束

不变贝塞尔-高斯光束引起了透明材料微加工应用的极大兴趣。零阶贝塞尔-高斯光束的小中心峰和细长的焦点区域为激光微加工提供了优势。然而，许多透明材料加工应用需要不对称光束来诱导定向裂纹。因此，在这项工作中，我们通过分析、数值和实验研究了由空间位移的半轴锥产生的光束，该光束在光束相位轮廓中引起非圆柱对称。找到并通过实验验证了分析解决方案。通过使用几何相位元素写入所需的光束相位变化，生成高功率和高质量光束。