Optical properties of potential-inserted quantum wells in the near infrared and Terahertz ranges

We propose an engineering of the optical properties of GaAs/AlGaAs quantum wells using AlAs and InAs monolayer insertions. A quantitative study of the effects of the monolayer position and the well thickness on the interband and intersubband transitions, based on the extended-basis sp3d5s⁎ tight-binding model, is presented. The effect of insertion on the interband transitions is compared with existing experimental data. As for intersubband transitions, we show that in a GaAs/AlGaAs quantum well including two AlAs and one InAs insertions, a three level {e1,e2,e3} system where the transition energy e3−e2 is lower and the transition energy e2−e1 larger than the longitudinal optical phonon energy (36 meV) can be engineered together with a e3−e2 transition energy widely tunable through the TeraHertz range.