THIS COMMUNICATION IS CANCELLED. Nanoacoustical strains in metal films generated by a few cycle femtosecond laser pulses

Irini Tzianaki , Evaggelos Kaselouris , Yannis Orphanos , Efthimios Bakarezos , Dimitris Zacharioudakis , Andreas Lyras , Michael Tatarakis , Costas Kosmidis , Nektarios Papadogiannis

High frequency nanoacoustical strains are generated in nanometer thick metal films deposited on appropriate substrate by the means of a few cycle femtosecond Ti:Sapphire laser pulses. The nanoacoustical strains are studied utilizing an ultrafast laser-displacement technique. The measured signal exhibits local maxima (or minima) at zero delay and at delays that correspond to the time that the acoustic echo arrives on metal film surface after reflection from metal-substrate interface. Changes on the temporal content of the few cycle femtosecond laser pulses seem to give rise in variations of the temporal characteristics of the laser generated nanoacoustic pulses. The selection of various metal films provides useful results which can be the base for theoretical models evaluation for the generation of this nanoacoustic stains by the extremely short duration laser pulses. In this temporal region, the non-thermal electrons, generated in the first moments of the few cycle femtosecond laser pulse metal surface excitation, seem to play significant role in the lately generated nanoacoutical strains.

Mots clés: picosecond ultrasonics; femtosecond laser pump – probe; frequency ultrasound; few cycle femtosecond pulses

Domaines: Acoustique [physics.class-ph]

Irini Tzianaki, Evaggelos Kaselouris, Yannis Orphanos, Efthimios Bakarezos, Dimitris Zacharioudakis, et al.. THIS COMMUNICATION IS CANCELLED. Nanoacoustical strains in metal films generated by a few cycle femtosecond laser pulses. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00811254⟩