Directed Self-Assembly of Single Quantum Dot Optical Devices

Techniques that allow one to control the nucleation site of individual, self-assembled quantum dots are necessary for the fabrication of optical and electronic devices that must align subsequent control structures to the dots. In this talk I will describe a ``nanotemplate deposition'' technique that allows one to direct the surface migration of deposited Indium species during crystal growth so that InAs quantum dot nucleation sites can be controlled \textit{a-priori} with nanometre precision. Using this technique one can construct high finesse, two-dimensional photonic crystal microcavity membranes in which the optical defect mode is aligned both spectrally and spatially to a single InAs/InP, site-selected quantum dot emitting at 1550nm. I will describe the fabrication and optical characterisation of such cavities, with Purcell factors in excess of 4,000 and mode volumes of approximately $0.5\left( {\lambda /n} \right)^3$, and I will illustrate how coupling to these cavities using a tapered nanowire micro-loop fiber can be used to optimize the extraction efficiency for single photon source applications.