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arXiv · 1308.6424

Influence of multi-electronic states on few-quantum-dot nanolasers

J. Liu·S. Ates·M. Lorke·J. Mørk·P. Lodahl·S. Stobbe
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Abstract

We present an experimental and theoretical study on the gain mechanism in a photonic-crystal-cavity nanolaser with embedded quantum dots. From time-resolved measurements at low excitation power we find that four excitons are coupled to the cavity. At high excitation power we observe a smooth low-threshold transition from spontaneous emission to lasing. Before lasing emission sets in, however, the excitons are observed to saturate, and the gain required for lasing originates rather from multi-electronic transitions, which give rise to a broad emission background. We compare the experiment to a model of quantum-dot microcavity lasers and find that the number of emitters feeding the cavity must greatly exceed four, which confirms that the gain is provided by multi-electronic states. Our results are consistent with theoretical predictions.

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J. Liu, S. Ates, M. Lorke, J. Mørk, P. Lodahl, S. Stobbe. 2013-08-29. Influence of multi-electronic states on few-quantum-dot nanolasers. https://arxiv.org/abs/1308.6424

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