A simulation of an optically pumped laser based on a ZnSe/Zn1?yCdySe double quantum well with a Zn1?xMnxSe diluted magnetic semiconductor barrier is presented. Giant Zeeman splitting in diluted magnetic semiconductors leads to splitting of electronic states, which in turn leads to tunability of laser wavelength by external magnetic field. Tunability is predicted throughout the wavelength range between 60 and 72??m at low temperatures.