Broadband Semiconductor Light Sources Operating at 1060 nm Based on InAs:Sb/GaAs Submonolayer Quantum Dots
IEEE J. Sel. Top. Quantum Electron., vol. 25, no. 6, pp. 1900310 (2019).
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In this paper, we investigate the potential of submonolayer-grown InAs:Sb/GaAs quantum dots as active medium for opto-electronic devices emitting in the 1060 nm spectral range. Grown as multiple sheets of InAs in a GaAs matrix, submonolayer quantum dots yield light-emitting devices with large material gain and fast recovery dynamics. Alloying these structures with antimony enhances the carrier localization and red shifts the emission, whereas dramatically broadening the optical bandwidth. In a combined experimental and numerical study, we trace this effect to an Sb-induced bimodal distribution of localized and delocalized exciton states. While the former do not participate in the lasing process, they give rise to a bandwidth broadening at superluminescence operation and optical amplification. Above threshold laser properties like gain and slope efficiency are mainly determined by the delocalized fraction of carriers.
1 Institut für Optik und atomare Physik, Technische Universität Berlin, 10623 Berlin, Germany
2 Institut für theoretische Physik, Technische Universität Berlin, 10623 Berlin, Germany
3 Institut für Festkörperphysik, Technische Universität Berlin, 10623 Berlin, Germany
4 Institute of Experimental Physics, Otto-von-Guericke-Universität Magdeburg, Fakultät für Naturwissenschaften, 39106 Magdeburg, Germany
5 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, 12489 Berlin, Germany
Quantum dots, semiconductor materials, semiconductor lasers, semiconductor optical amplifiers.