Characterization of fiber-generated entangled photon pairs with superconducting single-photon detectors.
We demonstrate the suitability of fiber-generated entangled photon pairs for practical quantum communications in the telecom band by measuring their properties with superconducting single-photon detectors that produce negligible dark counts. The photon pairs are created in approximately 5-ps duration windows at 50 MHz rate while the detectors are operated in ungated free running mode. We obtain a coincidence to accidental-coincidence ratio >80 with raw photon-counting data, i.e., without making any post-measurement corrections. Using a previously demonstrated counter-propagating scheme we also produce polarization-entangled photon pairs at 50-MHz rate, which in coincidence detection directly yield two-photon interference with a fringe visibility >98%.
Liang
Chuang
C
Lee
Kim F
KF
Medic
Milja
M
Kumar
Prem
P
Hadfield
Robert H
RH
Nam
Sae W
SW