The change in refractive index of AlGaAs/GaAs single quantum wells due to impurity-induced mixing

The authors report the results of some calculations of the effect of the width and shape of the quantum well on the change of the refractive index of a single 100 AA thick square GaAs quantum well with thick A1/sub 0.30/Ga/sub 0.70/As barriers. The refractive-index difference between implanted and unimplanted layers after impurity-induced mixing has been calculated for a variety of structures. The results show that a large refractive-index difference can be achieved for heavily mixed wide wells for use at longer wavelengths, while negative refractive-index changes can be predicted for the moderate mixing case. The application of these results to multiquantum-well waveguides also predicts the conditions for the transition between guiding and antiguiding in waveguides.<>