Product Code: ICA11_M705

Direct In-Situ Measurement of the Ablation Rate in Short Pulse Laser Percussion Drilling of Metal Targets
Authors:
Francesco Mezzapesa, Università Degli Studi and Politecnico Di Bari, CNR-IFN UOS Bari; Bari Italy
Antonio Ancona, CNR-IFN UOS Bari; Bari Italy
Teresa Sibillano, CNR-IFN UOS Bari; Bari Italy
Francesca di Niso, Università Degli Studi and Politecnico Di Bari; Bari Italy
Francesco de Lucia, Università Degli Studi and Politecnico Di Bari; Bari Italy
Maurizio Dabbicco, Università Degli Studi and Politecnico Di Bari, CNR-IFN UOS Bari; Bari Italy
Pietro Mario Lugarà, CNR-IFN UOS Bari, Università Degli Studi and Politecnico Di Bari; Bari Italy
Gaetano Scamarcio, Università Degli Studi and Politecnico Di Bari, CNR-IFN UOS Bari; Bari Italy
Presented at ICALEO 2011

Ultrashort-pulse laser ablation is a fast-establishing technology in precision laser micromachining of transparent as well as opaque materials. Direct measurements of physical parameters such as the penetration depth and the removal rate are crucial to improve the basic understanding of the ultrafast laser-material interaction. Furthermore, various dynamic factors related to the influence of laser pulse duration and peak energy have to be assessed by in-situ spatial- and time-dependent characterization all through the laser ablation process. We demonstrate that an all-optical detecting system based on feedback interferometry is capable to instantaneously measure the ablation front displacement and the laser ablation rate during ultrafast percussion drilling of metallic plates. Analyzing the sawtooth-like induced modulation of the interferometric signal out of the diode laser used as detector, the time dependence of hole penetration depth can be revealed with sub-micrometric resolution. This sensing technique can be easily integrated in most industrial workstations, enabling the development of on-line control methods to improve the ablation efficiency and the quality of laser micro-machining processes.