Optimal analysis of ultra broadband energy-time entanglement for high bit-rate dense wavelength division multiplexed quantum networks

F Kaiser (1) , D Aktas (1) , B Fedrici (1) , T Lunghi (1) , Laurent Labonté (1) , Sébastien Tanzilli (1)

1 LPMC - Laboratoire de physique de la matière condensée

We demonstrate an experimental method for measuring energy-time entanglement over almost 80 nm spectral bandwidth in a single shot with a quantum bit error rate below 0.5%. Our scheme is extremely cost-effective and efficient in terms of resources as it employs only one source of entangled photons and one fixed unbalanced interferometer per phase-coded analysis basis. We show that the maximum analysis spectral bandwidth is obtained when the analysis interferometers are properly unbalanced, a strategy which can be straightforwardly applied to most of today's experiments based on energy-time and time-bin entanglement. Our scheme has therefore a great potential for boosting bit rates and reducing the resource overhead of future entanglement-based quantum key distribution systems.

Domaines: Physique Quantique [quant-ph]

F Kaiser, D Aktas, B Fedrici, T Lunghi, Laurent Labonté, et al.. Optimal analysis of ultra broadband energy-time entanglement for high bit-rate dense wavelength division multiplexed quantum networks. Applied Physics Letters, 2016, 108, pp.231108. ⟨10.1063/1.4953785⟩. ⟨hal-01330127⟩