Probing ultrashort-pulse laser excitation of sapphire: From the initial carrier creation to material ablation
1 Department of Physics and Astronomy, Aarhus University - DK-8000 Aarhus C, Denmark
2 Laboratoire des Solides Irradiés/CEA IRAMIS, Ecole Polytechnique - Palaiseau, France
Received: 27 November 2013
Accepted: 5 February 2014
Ultrashort-pulse laser excitation of dielectrics has been investigated over a large span of intensities. Experimentally, single-shot studies on single-crystal sapphire samples combine time-resolved spectral interferometry with time-resolved reflectivity and ablation-rate measurements. The complete development of the excitation from the first creation of conduction-band electrons at low intensities to the formation of a highly excited plasma and associated material fragmentation is observed experimentally and explained by a single theoretical model, which combines material excitation in a multiple-rate equation description with light propagation.
PACS: 79.20.Eb – Laser ablation / 78.47.J- – Ultrafast spectroscopy (<1 psec) / 52.38.Mf – Laser ablation
© EPLA, 2014