Supersymmetric nitride-based semiconductor lasers

• Applicant: Professor Dr. Ulrich Theodor Schwarz
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 524962704

Fundamental lateral mode operation of edge-emitting lasers (EELs) can typically be achieved by using a sufficiently narrow or shallowly etched laser ridge. This in turn leads to small width of active area resulting in moderate emitted power. In addition, small width of active areas contributes to local generation of high thermal power density being problematic to dissipate. In this project we propose to adopt supersymmetry (SUSY) theory in a context of nitride-based lasers to boost their fundamental mode emission. SUSY enables widening the laser ridge and sustaining fundamental mode emission simultaneously, that will contribute to enhancement of optical power with high quality of the laser beam emitted by electrically driven devices. The project consists of three main objectives. First two are related to designing and realisation the SUSY-lasers operating under the pulse regime and at continuous-wave CW operation. Both aims require different designs of SUSY-lasers that will be investigated in the project. Third aim is related to experimental characterisation of the SUSY-lasers unveiling reach physics responsible for stable single mode operation. This new electrically driven laser configuration, that has never been studied experimentally nor theoretically, is a fascinating example of non-Hermitian physics that brings great promise for the enhancement of lasing properties not only of the configuration considered in the project, but also other in-plane lasers fabricated in all semiconductor material configurations including interband-cascade and quantum-cascade lasers, as well as vertical-cavity surface emitting lasers (VCSELs), fiber lasers etc. Therefore in this project we focus not only on improvement of nitride-based edge-emitting lasers properties but also on a thorough understanding of the fundamental physical phenomena occurring in SUSY-lasers concerning the role of the exceptional points and parity-time symmetry breaking, that are expected to play a key role in understanding the operational principles of SUSY-lasers.

• DFG Programme: Research Grants
• International Connection: Poland
• Cooperation Partner: Professor Dr.-Ing. Tomasz Grzegorz Czyszanowski