Ultrafast laser spatial beam shaping based on Zernike polynomials for surface processing.
Ultrafast laser spatial beam shaping based on Zernike polynomials for surface processing.
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基于泽尼克多项式的超快激光空间光束整形用于表面加工。
DOI：
10.1364/oe.24.006542
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发表时间：
2016
期刊：
影响因子：
3.8
通讯作者：
C. Mauclair
中科院分区：
文献类型：
--
作者：
J. Houzet;N. Faure;Mathieu Larochette;Anne‐Catherine Brulez;Stéphane Benayoun;C. Mauclair
在飞秒激光加工中，波前调制器可以实现光束的空间整形。波前调制器显示预先计算的相位掩模，该相位掩模调制激光波前以在加工平面中产生目标强度分布。由于波前调制器的非理想光学响应，实验分布可能与目标显著不同，特别是对于连续形状。我们提出了一种替代的相位掩模计算方法，可以适应相位调制器的光学性能。根据该性能，从可调节数量的Zernike多项式，最小二乘拟合算法数值地确定它们的系数以获得期望的波前调制。我们说明的技术与光学寻址的液晶光阀产生连续的强度分布匹配所需的烧蚀轮廓，而不需要一个波前传感器。实验激光分布的投影与计算结果相比，显示出5%的RMS误差。钢的烧蚀是根据模具表面上用户定义的微凹坑和微凹槽目标来实现的。微槽和注入的聚碳酸酯的轮廓与目标紧密匹配（RMS低于4%）。
In femtosecond laser machining, spatial beam shaping can be achieved with wavefront modulators. The wavefront modulator displays a pre-calculated phase mask that modulates the laser wavefront to generate a target intensity distribution in the processing plane. Due to the non-perfect optical response of wavefront modulators, the experimental distribution may significantly differ from the target, especially for continuous shapes. We propose an alternative phase mask calculation method that can be adapted to the phase modulator optical performance. From an adjustable number of Zernike polynomials according to this performance, a least square fitting algorithm numerically determines their coefficients to obtain the desired wavefront modulation. We illustrate the technique with an optically addressed liquid-crystal light valve to produce continuous intensity distributions matching a desired ablation profile, without the need of a wavefront sensor. The projection of the experimental laser distribution shows a 5% RMS error compared to the calculated one. Ablation of steel is achieved following user-defined micro-dimples and micro-grooves targets on mold surfaces. The profiles of the microgrooves and the injected polycarbonate closely match the target (RMS below 4%).
影响因子：
3.8
作者：
Jesacher, Alexander;Booth, Martin J.
通讯作者：
Booth, Martin J.