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

TL;DR

This paper demonstrates how inserting monolayers of AlAs and InAs into GaAs/AlGaAs quantum wells can tailor their optical properties, enabling tunable intersubband transitions in the near-infrared and Terahertz ranges.

Contribution

It introduces a method to engineer quantum well optical properties using monolayer insertions and provides a detailed theoretical analysis of their effects.

Findings

Insertion of monolayers modifies interband and intersubband transition energies.

A three-level system with tunable Terahertz transitions is achievable.

Theoretical results align with existing experimental data.

Abstract

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.