Quantum Tomography of a Bright, Polarization-Entangled Photon Pair Source Based on a Fiber Sagnac Interferometer

Published

September 16, 2007

Author(s)

Jingyun Fan, M D. Eisaman, Alan L. Migdall

Abstract

The success of many quantum-information applications demands entangled photon pairs emitted at a high rate, and in a single spatial mode with narrow spectral bandwidth to allow high two-photon interference visibility in creation and propagation. Here we report what we believe is the first experimental demonstration of a high-fidelity, bright, single-mode-optical-fiber source of polarization-entangled photons operated at room temperature. The source takes advantage of single-mode fiber optics, highly nonlinear microstructure fiber, judicious phase-matching, and the inherent stability provided by a Sagnac interferometer. With a modest average pump power (300 ?W), we create all four Bell states with a detected two-photon coincidence rate of 7 kHz per bandwidth of 0.9 nm in a spectral range of more than 20 nm. To characterize the purity of the states produced by this source, we use quantum-state tomography to reconstruct the corresponding density matrices, with fidelities of 95% or more for each Bell state.

Proceedings Title

Frontiers in Optics (FiO) | Annual Meeting | 91st | 2007 | OSA |

Conference Dates

September 16-20, 2007

Conference Title

Frontiers in Optics Conference

Pub Type

Conferences

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DOI Link

Keywords

accidnetal, bell state, coincidence, four-wave mixing, Raman scattering, Sagnac interferometer, tomography

Citation

Fan, J. , Eisaman, M. and Migdall, A. (2007), Quantum Tomography of a Bright, Polarization-Entangled Photon Pair Source Based on a Fiber Sagnac Interferometer, Frontiers in Optics (FiO) | Annual Meeting | 91st | 2007 | OSA |, [online], https://doi.org/10.1364/FIO.2007.PDP_C3 (Accessed October 11, 2025)