Application of laser doppler vibrometry to characterize the laser drilling process

Laser drilling is being used more and more frequently in many industries, such as the aerospace, medical and electronics industries, to produce precision bores. A wide range of technically difficult-to-machine materials are applied. Laser drilling has already been intensively researched in order to investigate the basic mechanisms of the drilling process and the influences of various machining parameters on the quality of the holes. These findings have explicitly led to more successful machining processes of various technical components and industries. Despite all the advantages, there are some limitations of the laser drilling process and thereby a demand for innovative solutions to increase productivity. This paper presents a novel approach to the characterisation of the laser drilling process through the analysis of the acoustic signal characteristics. The objective is to apply a new generation of optical microphones to detect key aspects of the laser drilling process. This enables the development of new strategies to optimize the laser processing parameters, increasing repeatability and productivity for industrial applications.