Skin effect in strongly inhomogeneous laser plasmas with weakly anisotropic temperature distribution

The absorption coefficient of an ultrashort, high-intensity S-polarized laser pulse is calculated for plasmas with weakly anisotropic electron energy distribution functions and high gradients of electron density. In the limiting cases of normal and anomalous skin depth effects, the plasma kinetic equation coupled to the Maxwell equations can be solved analytically for different relations between the laser wavelength, the electron density gradient scale length, and the skin depth. For anisotropic electron distribution functions, we obtained an increase of the laser absorption coefficient for transverse to longitudinal electron temperature ratio greater than one.