title: Double-heralded generation of two-photon-states by spontaneous four-wave-mixing in the presence of noise.
abstract: We present an experimental method for creating and verifying photon-number states created by non-degenerate, third-order nonlinear-optical photon-pair sources. By using spatially multiplexed, thresholding single-photon detectors and inverting a conditional probability matrix, we determine the photon-number probabilities created through heralded spontaneous four-wave-mixing. The deleterious effects of noise photons on reliable heralding are investigated and shown to degrade the conditional preparation of two-photon number states more than they degrade conditional single-photon states. We derive the equivalence between the presence of unwanted noise in the herald channel and loss in the signal channel of heralded experiments. A procedure for characterizing the noise-photon contributions, and a means of estimating the herald noise-free photon-number distribution is demonstrated.
authors.forename: Roger A
authors.initials: RA
authors.lastname: Smith
authors.forename: Dileep V
authors.initials: DV
authors.lastname: Reddy
authors.forename: Dashiell L P
authors.initials: DL
authors.lastname: Vitullo
authors.forename: M G
authors.initials: MG
authors.lastname: Raymer