Engel A, Steffen J, Herziger G
Appl Opt. 1974 Feb 1;13(2):269-73. doi: 10.1364/AO.13.000269.
Machining of small holes with arbitrary contours can be performed by focusing a laser beam with a modulated zone plate (MZP). MZP's use the structure of the Fresnel zone plate as the carrier of a modulation function, which contains complete information about the contour to be machined. Spherically corrected MZP's produce aberration-free images within a field angle of 10(-3) rad. It is shown that the background noise due to higher diffraction orders is unimportant under typical machining conditions. A manufacturing procedure for high resolution MZP's with up to 2500 zones etched in chromium or quartz layers deposited on glass substrates is discussed. As in-line holograms have properties similar to MZP's, a simple method of recording wavelength-shift corrected in-line holograms is described. Experiments performed with a stable single-mode Nd(3+)-YAG laser demonstrate that the MZP can be important tool for laser machining purposes.
通过使用调制波带片（MZP）聚焦激光束，可以对具有任意轮廓的小孔进行加工。MZP利用菲涅耳波带片的结构作为调制函数的载体，该调制函数包含了待加工轮廓的完整信息。经过球面校正的MZP在10^(-3)弧度的视场角内可产生无像差图像。结果表明，在典型的加工条件下，由高阶衍射引起的背景噪声并不重要。本文讨论了一种在玻璃基板上沉积的铬或石英层中蚀刻多达2500个区域的高分辨率MZP的制造工艺。由于同轴全息图具有与MZP相似的特性，本文描述了一种记录波长偏移校正同轴全息图的简单方法。使用稳定的单模Nd(3+)-YAG激光器进行的实验表明，MZP可成为激光加工的重要工具。
