Detection efficiency and dark pulse rate of Rockwell (SSPM) single photon counters

This paper describes direct photon counting data on several pixels of the Rockwell SSPM detector array, about which absolute single photon detection efficiencies and time responses were reported previously by Kwiat et al. The new data shows a substantially larger efficiency, 85%, and suggests that damage in the optical fiber employed in the earlier data was responsible for the lower number, 70%. When the results of this paper are analyzed using reasonable assumptions, one concludes that several improvements of the SSPM detector are still possible to bring the photon counting efficiency close to or larger than 95%