Laser Processing by Using Diffractive Optical Laser Beam Shaping Technique

Laser beam shaping and homogenization techniques are substantial to optimize a large number of laser-material processing applications and laser-material interaction studies.Diffractive optical elements (DOE) play important role in provision of the process-adapted laser beam shaping.In this paper, we present an approach for laser beam shaping by using innovative DOE.The circular Gaussian beam was transformed to a square flat-top intensity profile in the focal plane of the objective lens by using novel DOE from TOPAG Lasertechnik GmbH.About 95% of the laser energy was coupled in the main beam with a nearly perfect rectangular shape.Experimental results have been achieved by applying the shaped beam for laser microfabrication.The picosecond and nanosecond lasers with moderate beam quality (M 2 =1.5) were used in the experiment.The shaped laser beam was applied for direct laser ablation of metal film on the glass substrate, drilling in a silicon wafer, scribing of thin-film solar cells and other technical materials.This technique allows creating a rectangular-shaped flat-top intensity profile in the focal plane that shows distinct advantages in laser material processing.