Distribution of Time-Energy Entanglement over 100 km fiber using superconducting single-photon detectors

Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.
Optics Express (Impact Factor: 3.49). 05/2008; 16(8):5776-81. DOI: 10.1364/OE.16.005776
Source: PubMed


In this letter, we report an experimental realization of distributing entangled photon pairs over 100 km of dispersion-shifted fiber. In the experiment, we used a periodically poled lithium niobate waveguide to generate the time-energy entanglement and superconducting single-photon detectors to detect the photon pairs after 100 km. We also demonstrate that the distributed photon pairs can still be useful for quantum key distribution and other quantum communication tasks. (C) 2008 Optical Society of America.

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    • "Based on highly purified fibres, the technology is based on a band centered at the frequency where the losses are minimal [26]. This idea is also used in quantum fibre optics, see [18] who has measured the photon duration and noted an increase with distance in a 100 km optic fibre. The presence of fluctuations in combination with the attenuation of the probability related to the initial state imply that the importance of the fluctuations increases with time and distance. "
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