Ga ion implantation followed by rapid thermal annealing (RTA) was utilized to enhance the interdiffusion in GaAs/AlGaAs single QWs. In low temperature photoluminescence a blue shift of emission energy from 30 to 90meV was observed. The shift was found to be dependent on the implantation damage and as a function of the annealing temperature and time. The interdiffusion coefficient of 10 -15 10 -17 cm 2/s by RTA was calculated.