Characterization of the photon-number state of a narrow-band single photon generated from a cold atomic cloud

摘要

In this paper, we demonstrate homodyne tomography on a narrow-band heralded single photon generated from spontaneous four-wave mixing process in a cold atomic cloud. This is the first work that shows the photon-number state of the narrow-band single photons transmitted through electromagnetically-induced transparency window. The Wigner function of the optical state is demonstrated as a non-Gaussian state. The homodyne tomography provides an important route to characterize the single-photon source.