Light-matter interaction of Exciton Polaritons at Telecommunication Wavelengths (LIEPOLATE)

• Applicant: Professor Dr. Martin Kamp
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2011 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 192757433

This proposal targets the demonstration of an exciton-polariton laser in the 1.31 μm wavelength range. This will be enabled by the combination of novel dilute nitride materials grown on GaAs substrates in combination with established GaAs-based technology for the fabrication of high quality microcavity structures. Since dilute nitride quantum wells (QWs) enable emission in the telecommunication window around 1.31 μm (which is inaccessible with conventional nitrogen-free QWs on GaAs), this new approach will allow studies of the strong coupling of a QW exciton with a photonic mode of a microcavity at telecom wavelengths. After optimization of the dilute nitride QW quality, especially in terms of high structural homogeneity, reduced lateral composition fluctuations and carrier localization, these emitters will be incorporated into microcavities to drive this system into the strong-coupling regime. Here, hybridized quasi-particles called exciton-polaritons are formed. Exciton-polaritons can condense in the ground state if a critical population density is exceeded, and one observes the onset of so-called polariton lasing, which in contrast to photon lasers occurs without population inversion. This allows the realization of ultra-low threshold exciton-polariton laser devices at telecom wavelengths. In addition, the developments envisaged in this proposal will reveal new possibilities for studies of the fascinating properties related to exciton-polaritons, like e.g. superfluid phenomena, quantum phase transitions, logic devices, etc. at telecommunication wavelengths.

• DFG Programme: Research Grants
• International Connection: Poland
• Participating Persons: Professor Dr. Alfred Forchel; Professor Dr. Jan Misiewicz