Electrically pumped polariton lasers

Exciton-polaritons are bosonic quasiparticles formed by the strong interaction between photons and excitons. The bosonic nature of exciton-polaritons and their very light mass enable polariton condensation at high temperatures and low excitation densities. This makes polariton devices highly interesting for future photonic applications as they are able to outperform common semiconductor laser technologies. In order to achieve strong light-matter interaction, photon and exciton wavefunction need to overlap in energy and space which is most likely achieved in semiconductor microcavities that consist of top and bottom dielectric mirrors for photonic confinement of cavity photons and quantum well layers for quantum confinement of excitons.
We investigate GaAs-based micropillar polariton diodes grown by molecular beam epitaxy. An efficient electrical injection of charge carriers is ensured by depositing ring electrodes on top and gradually doping the dielectric mirrors. Our research in this area is focused on the unambiguous evidence for electrically induced polariton condensation without applying an external magnetic field as well as reducing the condensation threshold and figures of merit for condensation. We further aim at realising an electrically-driven polariton device at room-temperature by improving the current injection and polariton stability. This requires an optimization of the microcavity design, geometry and morphology.

back to research page