Characterization of waveguide-integrated single-photon detectors using integratedphotonic structures
Sonia M. Buckley, Alexander N. Tait, Jeffrey T. Chiles, Adam N. McCaughan, Saeed Khan, Richard Mirin, Sae Woo Nam, Jeffrey M. Shainline
We show several techniques for using integrated-photonic waveguide structures to simultaneously characterize multiple waveguide-integrated superconducting-nanowire detectors with a single fiber input. We demonstrate structures for direct comparison of detector performance of waveguide integrated detectors with various widths and lengths. We also demonstrate an integrated- photonic structure to achieve detection with a high dynamic range. This device allows a small number of detectors to count photons across many orders of magnitude in count rate. However, we find a stray light floor of -30 dB limits the dynamic range to three orders of magnitude. To assess the utility of the detectors for use in synapses in spiking neural systems, we measured the response with average incident photon numbers ranging from less than 10^-3 to greater than 10. We find that the detector response is identical across this entire range, indicating that synapses based on these detectors will be independent of the number of incident photons in a communication pulse. Such a binary response is ideal for communication in neural systems. We further demonstrate that the response has a linear dependence of output current pulse height on bias current with up to a factor of 1.7 tunability in pulse height. Throughout the work, we compare room-temperature measurements to cryogenic measurements. The agreement indicates room-temperature measurements can be used to determine important properties of the detectors.
, Tait, A.
, Chiles, J.
, McCaughan, A.
, Khan, S.
, Mirin, R.
, , S.
and Shainline, J.
Characterization of waveguide-integrated single-photon detectors using integratedphotonic structures, Physical Review Applied, [online], https://doi.org/10.1103/PhysRevApplied.14.054008
(Accessed May 16, 2021)