Ion‐implanted GaAs layers annealed by a Q‐switched ruby laser have been examined by ellipsometry and Hall measurements. The extinction coefficient is shown to be a function of implant fluence for 120KeV Mg ion implants. Depth profile of the implant damage (via the extinction coefficient) shows the damage peak position relative to the LSS peak to be fluence dependent. Effects of laser anneal are evaluated from extinction coefficient measurements as a function of depth into the substrate. depth profile data are also given for C, Te, and Ge implants. Finally, surface extinction coefficient and sheet resistivity measuremenmts are given as a function of incident laser energy for 120KeV Mg implants with 1015/cm2 fluence. The extinction coefficient shows a minimum for a laser energy density of about .2 J/cm2 and increases thereafter. The sheet resistivity which decreases at about .28 J/cm2 and is 750Ω/⧠ at .35 J/cm2, continues to decreases with increasing laser energy.