Efficient single-spatial-mode periodically-poled KTiOPO4 waveguide source for high-dimensional entanglement-based quantum key distribution
Tian Zhong, Franco N. Wong, Alessandro Restelli, Joshua Bienfang
We demonstrate generation of high-purity photon pairs at 1560 nm in a single spatial mode from a periodically-poled KTiOPO4 (PPKTP)waveguide. With nearly-lossless spectral ﬁltering, the PPKTP waveguide source shows approximately 80 % single-mode ﬁber coupling efficiency and is well suited for high-dimensional time-energy entanglement-based quantum key distribution. Using high count-rate self-differencing InGaAs single-photon avalanche photodiodes conﬁgured with either square or sinusoidal gating, we achieve > 1 Mbit/s raw key generation with 3 bits-per-photon encoding, and, to the best of our knowledge, the highest reported Franson quantum-interference visibility of 98.2 % without subtraction of accidental coincidences.
Photon Counting, Nonlinear optics, parametric processes, Quantum detectors, Quantum communications, Quantum information and processing.
, Wong, F.
, Restelli, A.
and Bienfang, J.
Efficient single-spatial-mode periodically-poled KTiOPO4 waveguide source for high-dimensional entanglement-based quantum key distribution, Optics Express
(Accessed October 1, 2023)