Monitoring Direct Laser Interference Patterning of metallic substrates using an infrared camera system

Direct Laser Interference Patterning (DLIP) is a technique that enables the fabrication of homogeneous microstructures in the micrometer and sub-micrometer range. Typically, the topography of these structures is evaluated ex-situ, using methods such as confocal microscopy or white light interferometry. However, these techniques are not suitable for real-time process observation due to their long measurement time. In this study, an Infrared camera system is used to explore the correlation between the captured average temperature during DLIP treatment and topographical parameters in real-time. The results show a linear relationship between the applied laser fluence (0.7 to 4.9 J/cm²) and the measured average temperature, as well as significant changes in surface roughness, skewness, and kurtosis within this fluence range. These findings suggest that the presented method could be used for in-situ indirect monitoring of topography during DLIP treatment, enabling quick identification of process fluctuations.