Based on the microscopic nonlocal optical response theory, the intersubband optical absorption properties in AlGa As/Ga As couple quantum wells（CQWs） are investigated for p-polarized states. The numerical results show that spatial nonlocality of optical responses can induce a radiation shift on optical absorption spectra due to nonlocal effects. The dependence of the radiation shift on the CQW structure and the applied electric field is clarified. It is also demonstrated that the maximal radiation shift and the least optical absorbance can be obtained by adopting an appropriate CQW structure and a suitable applied electric field. This work may provide some methods of designing the nanomaterials with controllable nonlocality and observing the spatial nonlocal effects in experiment.
