Acoustic probing of two-temperature relaxation initiated by action of ultrashort laser pulse

作者：Inogamov N A^*; Ashitkov S I; Zhakhovsky V V; Shepelev V V; Khokhlov V A; Komarov P S; Agranat M B; Anisimov S I; Fortov V E

来源：Applied Physics A-Materials Science & Processing, 2010, 101(1): 1-5.

DOI：10.1007/s00339-010-5765-2

Ultrashort laser pulse transfers metal into a two-temperature warm dense matter state and triggers a chain of hydrodynamic and kinetic processes-melting, expansion, stretching, creation of tensile stress and transition into metastable state. We study the response of aluminum film deposited on a glass substrate to irradiation by a pump laser pulse transmitted through glass. Several films with thicknesses from 350 to 1200 nm have been investigated. The smallest thickness is of the order of the heating depth d (T similar to)100 nm in Al. The d (T)-layer and the free rear side of the film are coupled through pressure waves propagating between them. Therefore, the processes within d (T)-layer affects the time dependent displacement Delta x (rear)(t) of the rear surface. We compare simulated and experimental dependencies Delta x (rear)(t) obtained by the pump-probe technique. It allows us to define a thickness of molten Al layer and explore the two-temperature processes occurring inside the heated layer.

• 出版日期2010-10