Quantifying the Momentum Correlation between Two Light Beams by Detecting One

Author(s): A. Hochrainer, M. Lahiri, R. Lapkiewicz, G. B. Lemos, A. Zeilinger

Journal: PNAS

Volume: 114

Page(s): 1508-1511

Year: 2017

DOI Number: 10.1073/pnas.1620979114

Link: Link to publication


We report a measurement of the transverse momentum correlation between two photons by detecting only one of them. Our method uses two identical sources in an arrangement, in which the phenomenon of induced coherence without induced emission is observed. In this way, we produce an interference pattern in the superposition of one beam from each source. We quantify the transverse momentum correlation by analyzing the visibility of this pattern. Our approach might be useful for the characterization of correlated photon pair sources and may lead to an experimental measure of continuous variable entanglement, which relies on the detection of only one of two entangled particles.

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