Potential-inserted quantum well design for quantum cascade terahertz lasers

TL;DR

This paper introduces a novel potential-inserted quantum well design for terahertz quantum cascade lasers, demonstrating significant performance improvements through atomistic modeling, potentially enabling room-temperature THz lasing.

Contribution

The paper presents a new quantum well design using monolayer InAs inserts, showing enhanced oscillator strength and relaxation properties compared to classical designs.

Findings

100% increase in oscillator strength per unit length

High, temperature-independent contrast in relaxation times

Potential for room-temperature THz lasing

Abstract

We report on a new design of terahertz quantum cascade laser based on a single, potential-inserted quantum well active region. The quantum well properties are engineered through single monolayer InAs inserts. The modeling is based on atomistic, spds* tight-binding calculations, and performances are compared to that of the classical three-well design. We obtain a 100% increase of the oscillator strength per unit length, while maintaining a high, nearly temperature-independent contrast between phonon-induced relaxation times of the upper and lower lasing states. The improved performances are expected to allow THz lasing at room temperature.