We explore a promising method of generating pure heralded single photons. Our approach is based on parametric downconversion in a periodically-poled waveguide. However, unlike conventional downconversion sources, the photon pairs are counter-propagating: one travels with the pump beam in the forward direction while the other is backpropagating towards the laser source. Our calculations reveal that these downconverted two-photon states carry minimal spectral correlations within each photon-pair. This approach offers the possibility to employ a new range of downconversion processes and materials like PPLN (previously considered unsuitable due to their unfavorable phasematching properties) to herald pure single photons over a broad frequency range.
@article{arxiv.0901.0873,
title = {Pure single photon generation by type-I PDC with backward-wave amplification},
author = {A. Christ and A. Eckstein and P. J. Mosley and C. Silberhorn},
journal= {arXiv preprint arXiv:0901.0873},
year = {2009}
}
Comments
8 pages, 3 figures, minor text changes and reformatting