This thesis describes optical measurements on nanophotonic devices with integrated electrically tuneable quantum dots. The quantum dots enable a range of non-linear behaviour, including single photon generation and the generation of entangled photonic states on-chip. Device behaviour can be controlled by applying electric fields to the devices, enabling fast switching and tuning of device behaviour.
A waveguide-coupled electrically-driven single-photon source is demonstrated. Electroluminescence from a single quantum dot is coupled to a single-mode suspended nanobeam waveguide. The number of quantum dots coupled to the waveguide is limited in order to isolate emission from a single source. The single-photon nature of the emission is confirmed using correlation measurements.
The non-linear behaviour of a quantum dot in a single mode photonic crystal waveguide is investigated. In this work three charge states of the same quantum dot are investigated using resonance fluorescence and resonant waveguide transmission. A strong non-linear effect is generated by the single quantum dot, enabling interactions between pairs of photons and the generation of a two photon bound state. Fast switching of the device is demonstrated by the application of an electric field.
A waveguide-coupled quantum optical filter is presented. This device utilises Fano interference in a QD-waveguide system to modulate a coherent photonic input, generating a bunched or antibunched output. The photon statistics of the output can be tuned by changing the bias applied to the device
