Adaptive process monitoring for laser micro structuring of electrical steel using Optical Coherence Tomography with non-colour corrected lenses

摘要

In laser material processing, precision and quality are important requirements, Therefore 100% quality inspection is essential. Optical Coherence Tomography (OCT) offers the possibility of testing process stability in-line. This paper applies OCT as an in-line quality control system at different scales concerning process implementation. Its aim is an upscaling of the sensor technology for laser micro-processing of electrical steel to increase the efficiency of electrical machines. While using the same beam path, a dynamic possibility had to be created to compensate the spot-offset between laser and sensor. For this, an additional pair of galvanometer-scanners was implemented into the setup to enable independent control of the measuring beam and subsequently compensate the offset.