The linear and nonlinear changes in the refractive index of a Poschl-Teller quantum well are studied. The Poschl-Teller potential can easily become asymmetric by a correct choice of its parameter set. We use this feature to investigate the intensity-dependent refractive index of a GaAs quantum well within the density matrix formalism. Numerical results reveal large values of linear and nonlinear changes in the refractive index. (C) 2006 American Institute of Physics.