Experimental study of spontaneous electric field generated by a laser plasma

We report investigations of a space-time structure of the electric field of laser plasma from a solid target. An ArF excimer laser with an intensity of I congruent to 10(8) W/cm(2) was used to produce the plasma on various targets placed in air at atmospheric pressure. A strong difference in both the amplitude (by more than 1-2 orders of magnitude) and the structure of the electric field for conductive and dielectric targets has been observed. The held distribution for a conductive target was found to correspond to a dipole configuration of charges in the laser plasma, while for the dielectric target a quadrupole configuration was revealed. Possible explanations and applications of the observed effect are discussed. (C) 1998 American Institute of Physics.