Response of a quasiparabolic quantum-well system to intense ir and dc fields

We study the nonlinear optical properties of quasiparabolic quantum-well systems with a potential 1/2${\mathit{m}}^{\mathrm{*}}$${\mathrm{\omega }}_0^2$${\mathit{z}}^2$+V(z), where V(z) is an anharmonic correction. First, we give the exact solution of the Schrödinger equation for a strictly parabolic quantum well with intense applied infrared (ir) and dc electric fields. We then treat the anharmonic potential V(z) perturbatively to obtain the analytical expressions for the density matrix and the electronic polarizations of the system. Interesting nonlinear optical effects of different orders of the ir and dc fields are obtained which we present explicitly at the same time.