Room-temperature single-photon sources: design, performance, and applications

Single photon sources are key devices for optical quantum information processing, miniaturized optical elements, as well as light standards. Several systems have been exploited so far such as semiconductor quantum dots, defect centers in diamond, alkali atoms, and parametric down-conversion sources. In this contribution we will review some of these sources and highlight their unique properties with respect to applications in quantum information processing. A focus lies on two different room temperature sources based on cavity-enhanced parametric down-conversion and on nitrogen-vacancy centers in diamond.