Enhanced electroabsorption in selectively doped (Ga,In)As/(Al,In)As asymmetric double quantum wells

We report enhanced electroabsorption in selectively doped (Ga,In)As/(Al,In)As asymmetric double quantum wells (ADQWs) by the use of real space electron transfer. The electron concentration in both the wide and narrow wells is investigated by field dependent absorption and photoluminescence spectroscopy. The results are compared to absorption changes in an undoped ADQW structure that utilizes the quantum confined stark effect. The doped modulator exhibits a significantly larger red shift with applied field than the undoped structure.