We have investigated the influence of concurrent above‐band‐gap laser illumination on the damage profile of GaAs/AlGaAs heterostructures subject to low energy (sub‐keV) Ar+ ion bombardment. A dramatic change in damage profile was observed for these samples, compared with those that were not laser illuminated, and the degradation increases with the illuminated power intensity. Below‐band‐gap illumination results in a minimal increase in damage profile. Such results indicate the possibility of radiation‐enhanced diffusion of defects, and may explain the observed high defect diffusivity at room temperature.