• DOI:10.1364/JOSAB.31.003088
• Corpus ID: 117529527

Measuring the entanglement of photons produced by a nanosecond pulsed source

@article{Aguero2013MeasuringTE,
  title={Measuring the entanglement of photons produced by a nanosecond pulsed source},
  author={M'onica B. Aguero and Alejandro Andr{\'e}s Hnilo and Marcelo G. Kovalsky},
  journal={Journal of The Optical Society of America B-optical Physics},
  year={2013},
  volume={31},
  pages={3088-3096}
}

• M'onica B. Aguero, A. Hnilo, M. Kovalsky
• Published 9 December 2013
• Physics
• Journal of The Optical Society of America B-optical Physics

A source of entangled photons based on well-separated laser pump pulses (PDs) with a duration in the nanosecond range may be useful in many applications. Yet, such a source has intrinsic problems arising from the simultaneous arrival of signal and noise photons to the detectors, which makes the methods unsuitable for dealing with accidental (or spurious) coincidences applied in the continuous-wave or mode-locked pump regimes. Those problems are analyzed, and practical methods to calculate the number of accidental coincidences are described and experimentally checked. These methods are useful not only to measure entanglement, but also in every situation where extracting the number of valid two-photon coincidences from noisy data generated by such a pulsed process is required. As an original example of the use of these methods, we present the time-resolved measurement of the concurrence of the field produced by spontaneous parametric downconversion with PDs of duration in the ns range at a repetition of kHz.