A detailed study of the electromagnetic field's configuration inside plasma
s generated on solid surfaces by ultrashort laser pulses is given in the pr
esent work. The radiation due to the nonrelativistic motion of the electron
s in the overdense region is considered the main source of high harmonics,
whose polarization dependence on the fundamental beam is treated to explain
the experimentally observed polarization properties of the harmonics. (C)
2001 Elsevier Science B.V. All rights reserved.