Single photon emission from colored centers in diamond

Summary form only given. The realization of an efficient source of single photons synchronized on an external clock is an important goal for quantum cryptographic communication systems. More generally, this type of source would also be a very useful tool in the rapidly developing field of quantum information. A confocal imaging set-up with avalanche photodiodes enables us to realize photon correlation experiments with a ns time resolution. We have observed antibunching of photon emission of such centers on ns time scale. On time scale larger than 10 ns, shelving in a metastable state leads to the observation of photon bunching.