Nonlinear optical effects of exciton-polaritons in semiconductor microcavities in the near infrared to the ultraviolet range of wavelengths

Exciton-polaritons (EP) are half-light, half-matter quasiparticles arising from the strong coupling of photons with excitons, the elementary excitations of semi-conductors. In this thesis, we give a literature review on the state-of-the-art of research using exciton-polaritons and give examples of original research.

We start by defining exciton-polaritons in a bulk material and show why they cannot be observed directly in such a system. We give examples of systems to confine light in a cavity to overcome this limitation. This allows us to define the weak and strong coupling regimes of light and matter. Some example of research in exciton-polaritons is given, in particular in the materials which we will use later in this thesis.
An overview of the experimental techniques commonly used to study EPs is given. Our original research consists of three chapters covering a wide range of research topics. In the first chapter describing our results, we show the fabrication process of ring resonator structures, which demonstrate polariton lasing in the UV range up to room temperature. In a second chapter, we study, for the first time, exciton-polariton non-linearities in a Cu2O microcavity, in the visible range of wavelength. We demonstrate Kerr-like nonlinearity arising from the phenomenon of polariton Rydberg blockade. These two chapters have been published in the literature. Supplementary material related to these publications can be found at the end of the thesis in the appendices.
The final chapter describes experimental work still in progress, to realise an analogue black hole using exciton-polaritons in GaAs high quality sample, pumped in the near infrared. We provide motivation and show polariton superfluid-like behaviour appearing after a threshold. We create polariton vortices with very high orbital angular momentum, with the ultimate goal of realising an acoustic analogue black hole system. We conclude with a summary showing the highlights of the different chapters as well as the perspectives for further work offered by our results.