Nonlinear optical rectification associated to exciton states in asymmetric coupled double quantum wells

In this work the variational method is applied within the framework of the parabolic band and effective mass approximations, in order to study the 1s-like exciton energy spectrum in the GaAs–Ga 1−xAlxAs asymmetric coupled double quantum well configuration. The obtained states are then used to calculate the coefficient of nonlinear optical rectification associated to the transitions between the excitonic levels. It is shown that different exciton interstate transitions can lead to comparable optical rectification responses. With few exceptions, the increase of the system dimensions implies the appearance of a redshift in the resonant peak positions as well as the fall of their amplitudes.