Single photons sources are one of the key elements in emerging quantum technologies but, so far, there were a lack in a standardized way to characterize them.

Quantum Optics research group of INRIM have lead the first pilot study for the metrological characterization of single photon sources, exploiting their knowledge on the development of single photon sources in nitrogen–vacancy centre in diamond, thanks to the long lasting collaboration with University of Torino and INFN.

Ekaterina Moreva and colleagues from the National Metrology Institutes of Italy, Germany and the UK have then joined forces to develop the first standardized technique to characterize single-photon sources and to provide common uncertainty estimation procedures.  In the paper, published on Metrologia [1], the authors presented the technique exploited in the comparison, the first step towards a standardized method for the characterization of single photons emitters.

In February 2019, the prestigious journal Nature Physics stressed the importance of this study in its Research Highlights [2].