Mode Competition in Dual-Mode Quantum Dots Semiconductor Microlaser

TL;DR

This paper models quantum dots lasers to identify conditions for stable dual-mode operation in the THz range, highlighting the advantages of quantum dots over other gain media for THz photomixing applications.

Contribution

It evaluates various models for quantum dots lasers and demonstrates stable dual-mode operation is achievable with quantum dots as the active medium.

Findings

Stable dual-mode operation possible with quantum dots

Quantum well or bulk media lead to bistability

Quantum dots suited for THz photomixing applications

Abstract

This paper describes the modeling of quantum dots lasers with the aim of assessing the conditions for stable cw dual-mode operation when the mode separation lies in the THz range. Several possible models suited for InAs quantum dots in InP barriers are analytically evaluated, in particular quantum dots electrically coupled through a direct exchange of excitation by the wetting layer or quantum dots optically coupled through the homogeneous broadening of their optical gain. A stable dual-mode regime is shown possible in all cases when quantum dots are used as active layer whereas a gain medium of quantum well or bulk type inevitably leads to bistable behavior. The choice of a quantum dots gain medium perfectly matched the production of dual-mode lasers devoted to THz generation by photomixing.