The research topic of nano-optics deals with light-matter interactions on nano-scale dimensions. In Sheffield we are interested in two different aspects of the subject: the interaction of light with nano-structures such as quantum wires and dots, and the confinement of light in nano-scale cavities within photonic crystals. The two aspects are united when we investigate quantum dots in resonance with photons in nanocavities. The cavity enhances the interaction between the photon and the dot, and results in cavity QED phenomena such as the Purcell effect and strong coupling.
The research activity on nano-optics is funded by our EPSRC Programme grant on Semiconductor Integrated Quantum Optical Circuits. As part of this programme, we are investigating the generation of single photons by quantum dots and wires, and their integration with miniature photonic circuits on semiconductor chips. We are also investigating the use of resonant lasers to perform coherent quantum control experiments of individual exciton and spin states in quantum dots. By combining these two techniques, our goal is to interface static qubits (exciton or spin states in quantum dots) with flying qubits (photons), in order to demonstrate the key components of quantum networks.