The following three pilot comparisons were performed at INRIM, with the participation of CMI, NPL and PTB, from 16-27 October 2017

Detection efficiency:

At 1550 nm, on a fibre-coupled free-running single-photon avalanche detector (idQuantique ID220).

Glauber second-order auto-correlation function of a  single-photon source:

At 710 nm, on emission from a nitrogen vacancy centre in diamond;
At 1550 nm, on emission from a heralded single-photon source.