title: High-resolution monitoring of the hole depth during ultrafast laser ablation drilling by diode laser self-mixing interferometry.
abstract: We demonstrate that diode laser self-mixing interferometry can be exploited to instantaneously measure the ablation front displacement and the laser ablation rate during ultrafast microdrilling of metals. The proof of concept was obtained using a 50-μm-thick stainless steel plate as the target, a 120 ps/110 kHz microchip fiber laser as the machining source, and an 823 nm diode laser with an integrated photodiode as the probe. The time dependence of the hole penetration depth was measured with a 0.41 µm resolution.
authors.affiliation: Dipartimento Interateneo di Fisica, Università degli Studi e Politecnico di Bari, Bari, Italy. francesco.mezzapesa@uniba.it
authors.forename: Francesco P
authors.initials: FP
authors.lastname: Mezzapesa
authors.forename: Antonio
authors.initials: A
authors.lastname: Ancona
authors.forename: Teresa
authors.initials: T
authors.lastname: Sibillano
authors.forename: Francesco
authors.initials: F
authors.lastname: De Lucia
authors.forename: Maurizio
authors.initials: M
authors.lastname: Dabbicco
authors.forename: Pietro Mario
authors.initials: PM
authors.lastname: Lugarà
authors.forename: Gaetano
authors.initials: G
authors.lastname: Scamarcio