Double-crystal x-ray diffraction and topography, along with Raman spectroscopy and topography are used to study lattice reconstruction and carrier activation for pulsed laser annealed Si implanted GaAs. Although lattice strain is essentially eliminated, along with the production of carrier concentrations to about 3×1019 cm.3 at the center of laser annealed spots, incomplete removal of implant induced disorder and little dopant activation are observed in surrounding areas. Correlations of Raman and x-ray topographs suggest that concentric regions of partial melting, but without epitaxial regrowth, occur in the periphery of the laser annealed spots.