Single photon sources for absolute radiometry – A review about the current state of the art

In this presentation a review about the current state of the art concerning the application of deterministic single photon sources for absolute radiometry, i.e. the calibration of single photon detectors, is given. At the Physikalisch-Technische Bundesanstalt, the German national Metrology institute, an extensive research is carried out to optimize single photon sources for this purpose. Different single photon sources are currently under investigation, these are sources based on defect centres in (nano-)diamonds, on molecules and on semiconductor quantum dots.