Fiber-based in-situ surface characterization for laser material processing

In this paper, the utilization of a fiber-based laser line-scan confocal optical system for in-situ surface characterization in laser material processing systems is explored with the overarching objective to enable (near) real-time process control. The line-scan system operates at a low numerical aperture to enable installing multiple systems in parallel and to provide a sufficient working distance for protection of the optics from heat and fumes at the work surface. In experiments, the feasibility of determining surface roughness with the aid of data processing through a deep neural network and of distinguishing surface features was investigated. A method for measuring the height differences between different areas of samples was developed and demonstrated in proof-of-concept experiments.