Single optical mode coupling of single quantum dot spontaneous emission

Experiments conducted in the early 1980s showed that the spontaneous emission from single atoms can be modified using electromagnetic cavities in the microwave regime. In a condensed matter analogy, we demonstrate that the spontaneous emission from an isolated InAs quantum dot can be coupled with high efficiency to a single, polarization-degenerate cavity mode using an all-epitaxial compact structure. The quantum dot is embedded in a planar epitaxial microcavity, which is processed into a post of sub-micron diameter. The single quantum dot spontaneous emission lifetime is reduced from the noncavity value of 1.3ns to 280ps, resulting in a single-mode spontaneous emission coupling efficiency of 78%. It is believed that this structure will useful in triggered photons sources for quantum cryptography.