Calibration of free-space and fiber-coupled single-photon detectors
Thomas Gerrits, Alan L. Migdall, Joshua C. Bienfang, John H. Lehman, Sae Woo Nam, Oliver T. Slattery, Jolene D. Splett, Igor Vayshenker, Chih-Ming Wang
We present our measurements of the detection efficiency of free-space and fiber-coupled single- photon detectors at wavelengths near 851 nm and 1533.6 nm. We investigate the spatial uniformity of one free-space-coupled silicon single-photon avalanche diode (SPAD) and present a comparison between fusion-spliced and connectorized fiber-coupled single-photon detectors. We find that our expanded relative uncertainty for a single measurement of the detection efficiency is as low as 0.7 % for fiber-coupled measurements at 1533.6 nm and as high as 1.8 % for our free-space characterization at 851.8 nm.