Intersubband transitions in InGaAs/AlAs coupleddouble quantum wellstructures for multi-wavelength all-optical switching

Abstract
A coupled double quantum well (C-DQW) structure enabling ultrafast, multi-wavelength, all-optical modulation using intersubband transitions, is proposed. It has been shown from the calculation of absorption spectrum and relaxation characteristics that an InGaAs/AlAs C-DQW structure is desirable for application to all-optical switches for multi-wavelength operation at near-infrared wavelengths down to 1.5 µm.