The interaction of low-intensity femtosecond laser pulses with a copper foil

Summary form only given.The results of experimental and theoretical research on interaction of femtosecond laser pulses at a wavelength 800 nm and 400 nm with a copper foil are presented. Ti:Sapphire laser intensity on foil surface was in the rang of 10
¹²
-3*10
¹⁴
W/cm
²
in these experiments that were carried out at University of Alberta (Canada). The calculations of femtosecond laser pulses interaction with a matter and study of the foil blow-off are performed with using of ID ERA code developed in RFNC-VNIITF. The hydrodynamic and electron conductivity with degeneracy effects were taken into account. Wide-range equations of state for solid, gas and plasma were used in ERA-code simulations. Two- temperature case was considered in these calculations by taking into account of energy exchange between electrons and phonons (ions). Laser energy absorption was calculated from Helmholtz equation with complex dielectric permittivity. The scattering of electrons on phonons and free electrons was taken into account in calculation of dielectric permittivity. The results of ERA code calculations are in a good agreement with data on laser light reflection that have been obtained earlier in experiments on interaction of 150-fs laser pulses with copper foils at University of Alberta. ERA code simulations of foil dynamic under action of 100-fs laser pulse with wavelength of 800 nm and intensity of 3*10
¹³
W/cm
²
were performed as with low-intensity nanosecond prepulse as without it. It is shown that nanosecond prepulse at intensity of 10
⁸
W/cm
²
- 10
⁹
W/cm
²
have no significant influence on copper foils.