Applying beam shaping optical components is important in various modern laser micromachining technologies like drilling holes, scribing, patterning. Typically micromachining systems contain such components like F-theta lenses, beam expanding and scanning optics like 2- and 3-axis galvo mirror scanners, therefore using of beam shapers require building of special optical systems combining all optical components. As the beam shaping optics it is suggested to apply field mapping refractive beam shapers like Shaper having some important features: low output divergence, high transmittance, extended depth of field, capability to work with TEM00 and multimode lasers, as result providing a freedom in building various optical systems. De-magnifying of flattop laser beam is realized with using imaging technique; the imaging optical system to be composed from F-theta lens of scanning head and additional collimating system to be used right after a Shaper. One of technical tasks in this approach is implementation of compact design of the collimating part, another task – simple switching between final spot sizes. As a solution it is suggested to apply a specially designed Beam Shaping Unit, which is based on a Shaper and combination of mirrors, locating between a laser and a scanning head; the functions of that combined system are: conversion from Gaussian to flattop laser beam irradiance profile, compact design, alignment features, easy adaptation to a laser and a scanning head used in particular equipment, stepwise switching between resulting spot sizes. There will be considered design features of refractive beam shapers and Beam Shaping Unit, examples of optical layouts to generate flattop laser spots, which sizes span from several tens of microns to millimetres. Examples of real implementations and results of material processing will be presented as well.

Date Published: 20 February 2015
PDF: 9 pages
Proc. SPIE 9346, Components and Packaging for Laser Systems, 934615 (20 February 2015); doi: 10.1117/12.2081171

Published in SPIE Proceedings Vol. 9346:
Components and Packaging for Laser Systems
Alexei L. Glebov; Paul O. Leisher, Editor(s)