By: Dr. Alexander Laskin
Molecular Technology (MolTech) GmbH, Berlin, Germany
Homogenizing of intensity profile of laser beam brings to additive laser technologies effects that improve the performance of those technologies comparing to what can be achieved with “usual” non-uniform laser beams: the processes become more stable, less tough positioning tolerances make the technologies easier to use, more efficient using of laser energy leads to costs reduction. This homogenization is successfully realized with refractive beam shapers of field mapping type pShaper intended to transform Gaussian or similar intensity profiles to flattop, “inverse Gauss” and other profiles with keeping consistency of a laser beam. The refractive beam shapers can be used with TEM00 and multimode laser beams, low inherent losses allow using them with powerful laser sources, particular models can be implemented either as Galilean Telescope without internal focusing or as Collimators. Low output divergence makes it possible to manipulate the beam with using additional optical elements to vary the final spot size and realize not only round spots, but also linear spot shapes. The Collimator versions are very convenient to be applied with powerful fiber sources like fiber coupled solid state and diode lasers, or fiber lasers.
There are described principles of operation, design features of the refractive field mapping beam shapers pShaper as well as presented examples of beam intensity transformation and effects on material processing achieved in several industrial applications.
An example of generation of linear profile is shown in figure below.