Heralding pure single photons: a comparision between counter-propagating and co-propagating twin photons

Abstract

We investigate different strategies suitable to generate pure heralded single photons through spontaneous parametric down-conversion, comparing the counter-propagating geometry studied in [1] with more conventional co-propagating configurations which enhance the purity of the heralded photon state through the technique of group-velocity matching. Our analysis is based on the correlation of twin photons in the temporal domain,a non-standard approach that provides a physical view of the mechanisms that permit to eliminate the temporal entanglement of the state and to generate high-purity heralded photons. The Schmidt number associated to the temporal modes, which provides a more quantitative estimate of the purity, is then calculated. The efficiency of the various strategies and the individual properties of the heralded photons thereby generated are also compared.

21 pages, 7 figures

References in corpus (7)

• Heralded Generation of Ultrafast Single Photons in Pure Quantum States
• Probing multimode squeezing with correlation functions
• Optimal Co-linear Gaussian Beams for Spontaneous Parametric Down-Conversion
• Conditional preparation of single photons using parametric downconversion: A recipe for purity
• Bright source of spectrally uncorrelated polarization-entangled photons with nearly single-mode emission
• Pure single photon generation by type-I PDC with backward-wave amplification
• Counter-propagating spontaneous four wave mixing: photon-pair factorability and ultra-narrowband single photon

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• On-Chip Generation of Co-Polarized and Spectrally Separable Photon Pairs