Relative calibration techniques for characterising single photon detectors

In this paper, we will discuss two optical fibre assisted approaches towards a relative calibration of a single photon avalanche diode (SPAD). One is adopted from optical telecommunication. Here, the incoming photon flux is divided into two arms of a fibre optical beam splitter and send to the device under test (DUT), an id100-50 module (idQuantique) and the standard detector, a SPCM-13 module (PerkinElmer). In order to determine the beam splitter ratio as well as the measurement uncertainty caused by the fibre coupling, the two fibre arms are interchanged over several runs. From the ratio of the measured detector count rates, the relative detection efficiency of the DUT compared to that of the standard SPAD is determined. Here, we obtain 0.121±0.001 for the id100-50 detector with respect to the SPCM-13 module.