Theoretical study of a quantum dot microcavity laser

Here we theoretically investigate a new laser device structure model based on a single semiconductor quantum dot (QD) gain emitter, where the lasing occurs through discrete conduction states. A single QD is selectively placed in a high quality microcavity, called a microdisk, which is resonant with an intersublevel QD transition. The quantitative results of fully quantum-mechanical treatment here show that, when adjusting the QD-cavity coupling parameters to be appropriate values, the microcavity coupling mode would lead to a very high photon intensity of the single QD microcavity laser. The QD-cavity coupling interaction is modeled in the strong-coupling regime, and we conclude that the present QD microcavity system itself can serve as a new novel terahertz laser with low threshold.