In this work we present a calculation of the infrared optical absorption coefficient for a Ga1-xAl xAs quantum well (QW) as a function of donor impurity concentration, compensation and temperature. We treat this problem using a Self-Consistent Method (SC) calculation taking into account donors as major impurities. The Variational Method was used to obtain the ground state wave-function of an electron bound to a donor impurity in a QW. The results show a shift of energy in the absorption coefficient.