Exciton-polaritons are quasi-particles comprising superposition states of photons and excitons in semiconductors. As such they display properties of both species, and can combine light-speed processes resulting from the photonic component with Coulomb interactions resulting from the exciton component. These properties hold promise for devices such as ‘threshold-less’ lasers and ultrafast nonlinear optical switches.
This project will investigate the fabrication of exciton-polariton light source devices using 2D semiconductor materials in optical microcavities. Transition metal dichalcogenides such as WS2 offer large exciton binding energies such that coupling to microcavities can lead to polariton formation at room temperature. Small volume (~λ3) tunable microcavities will be fabricated and used to create these polariton effects, which will be analysed using laser spectroscopy. The goal of the project will be to observe nonlinear behaviour at room temperature with a view to realisation of practical devices.