Single quantum dot lasers and coupled cavity arrays

• Applicants: Professor Dr. Christopher Gies; Professor Dr. Martin Kamp; Professor Dr. Stephan Reitzenstein
• Subject Area: Experimental Condensed Matter Physics ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas ; Theoretical Condensed Matter Physics
• Term: from 2015 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 269240809

The goal of this project is the realization and investigation of single emitter lasers and coupled laser arrays on the basis of semiconductor quantum dots. The regime of single-emitter lasing fundamentally differs from that of conventional lasers and offers novel and intriguing physical concepts and applications. Such lasers are driven by quantum- and correlation effects that are, currently, not completely understood. In addition to their theoretical description and conceptual understanding the technological realization and experimental characterisation provide demanding challenges. By combining microscopical modelling, quantum-optical spectroscopy and nano-scale sample preparation, the project aims at providing a conclusive understanding of single-emitter lasers. One way of achieving this will be to use resonant, as well as two-color excitation schemes in microcavity resonators with ultra-high quality factors and low quantum-dot density.A particular focus is on electrically pumped single-emitter lasers that are of highest relevance for efficient low-power optoelectronic devices. This topic lends from the expertise gained in the investigations of these systems under optical excitation. The realization and understanding of these new laser forms will be a milestone in the development of novel sources of photons with tunable statistical properties. A further innovative sub-project adds to this by coupling several single-quantum-dot lasers to a laser array, which will form the basis of studies on collective effects in and outside the lasing regime.The close and intensive collaboration between theory, technology and experiment is key to the project. Sample preparation and spectroscopy will benefit from the input and feedback drawn from microscopical models. This will lead to the full description and fundamental understanding of the underlying physical processes, enabling quantitative predictions of single-emitter lasing activity in future applications.

• DFG Programme: Research Grants