Abstract :
A new approach has been used for the fabrication of light-modulation and switching devices with the goal of producing a large Stark effect. A large tunability of the transition energy under an applied electric field is observed in the intersubband optical transition in the View the MathML source step quantum-well structure consisting of an In0.65Ga0.35As quantum well and an In0.53Ga0.47As quantum well. The electronic subband energies and the wavefunctions in View the MathML source step quantum wells under an applied electric field are calculated by a transfer matrix method taking into account strain effects. The absorption peak and the Stark shift are much more sensitive to the applied electric field than in the single-well case. These results indicate that large Stark shifts are achieved for View the MathML source step quantum wells and that the step quantum wells may have very interesting applications for low-current and high-speed optoelectronic devices.
