Time-resolved study of laser-induced breakdown in dielectrics

• Published in: Europhysics letters Vol. 56; no. 1; pp. 138 - 144
• Main Authors: Quéré, F, Guizard, S, Martin, Ph
• Format: Journal Article
• Language: English
• Published: Les Ulis IOP Publishing 01.10.2001; EDP Sciences; EDP sciences
• Subjects: 72.20.Ht; 78.47.+p; 82.50.Pt; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric breakdown and space-charge effects; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Physics; Femtosecond; Time resolution; Inorganic compounds; Electric breakdown; Laser radiation; Oxides; Multi-photon processes; Excited states; Experimental study; Carrier density; Pulsed lasers
• ISSN: 0295-5075; 1286-4854
• DOI: 10.1209/epl/i2001-00499-9

We present the first femtosecond time-resolved study of the evolution of the laser-excited carrier density with the laser intensity, in various dielectrics of practical interest (SiO2, Al2O3, MgO) both above and below the breakdown threshold. These measurements demonstrate that the high electronic excitation responsible for optical breakdown in these solids is produced by multiphoton absorption by valence electrons, for pulses shorter than a few ps. No sign of electronic avalanche has been observed for such short pulses.