Active semiconductor nanophotonics based on deterministic quantum wire and dot systems

We investigate the use of MOVPE-grown ordered nanostructures on non-planar substrates for quantum nano-photonics and quantum electrodynamics-based applications. The mastering of surface adatom fluxes on patterned GaAs substrates allows for forming nanostrucutres confining well-defined charge carrier states. An example given is the formation of quantum dot (QD) molecules tunneled-coupled by quantum wires (QWRs), in which both electron and hole states are hybridized. In addition, it is shown that the high degree of symmetry of QDs grown on patterned (111)B substrates makes them efficient entangled-photons emitters. Thanks to the optimal control over their position and emission wavelength, the fabricated nanostructures can be efficiently coupled to photonic nano-cavities. Low-threshold, optically pumped QWR laser incorporating photonic crystal (PhC) membrane cavities are demonstrated. Moreover, phononmediated coupling of QD exciton states to PhC cavities is observed. This approach should be useful for integrating more complex systems of QWRs and QDs for forming a variety of active nano-photonic structures.