Fast electronic and thermal processes in femtosecond laser ablation of Au

Velocity distribution, pulse width dependence studies, and two-pulse correlation measurements have been used to study the possibility of the occurrence of ultrafast electronic and thermal ablation processes in Au exposed to ultrashort laser pulses in the femtosecond to picosecond time domain. Three distinct different velocity groups (5.5, 1.5, and 0.25eV) have been observed and can be attributed to two ultrafast electronic processes (Coulomb explosion and rapid plasma formation) and a thermal process. The buildup of a rapid plasma favors the laser energy absorption around 400fs after the beginning of the laser-matter interaction.

[1]  Gerhard Betz,et al.  Ultra-short laser ablation of metals and semiconductors: evidence of ultra-fast Coulomb explosion , 2006 .

[2]  K. Sokolowski-Tinten,et al.  Femtosecond x-ray measurement of ultrafast melting and large acoustic transients. , 2001, Physical review letters.

[3]  K. Bennemann,et al.  Transport and dynamics of optically excited electrons in metals , 2000 .

[4]  Storz,et al.  Electron thermalization in gold. , 1992, Physical review. B, Condensed matter.

[5]  Wladimir Marine,et al.  Cluster emission under femtosecond laser ablation of silicon , 2004 .

[6]  E. Campbell,et al.  Surface charging and impulsive ion ejection during ultrashort pulsed laser ablation. , 2002, Physical review letters.

[7]  Roger Kelly,et al.  Critical assessment of thermal models for laser sputtering at high fluences , 1995 .

[8]  J. Gillaspy,et al.  Nanoscale modification of silicon surfaces via Coulomb explosion , 1997 .

[9]  K. Sokolowski-Tinten,et al.  Femtosecond melting and ablation of semiconductors studied with time of flight mass spectroscopy , 1999 .

[10]  M. Bonn,et al.  Coulomb explosion in femtosecond laser ablation of Si(111) , 2003 .

[11]  Schmidt,et al.  Dynamics of laser desorption and ablation of metals at the threshold on the femtosecond time scale , 2000, Physical review letters.

[12]  S. Fourmaux,et al.  Non-thermal melting in semiconductors measured at femtosecond resolution , 2001, Nature.

[13]  K. Bennemann,et al.  Theory for the dynamics of excited electrons in noble and transition metals , 2002 .

[14]  K. Sokolowski-Tinten,et al.  Timescales in the response of materials to femtosecond laser excitation , 2004 .

[15]  V. Schmidt,et al.  Ultrashort laser ablation of metals: pump–probe experiments, the role of ballistic electrons and the two-temperature model , 2002 .