Mode competition in a dual-mode quantum-dot semiconductor microlaser

摘要

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