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Indistinguishable single-mode photons from spectrally engineered biphotons

Published

Author(s)

Thomas Gerrits, Adriana E. Lita, Sae Woo Nam, Changchen Chen, Jane Heyes, Kyung-Han Hong, Jeffrey Shapiro, Franco N. Wong

Abstract

We use pulsed spontaneous parametric down-conversion in KTiOPO4, with a Gaussian phasematching function and a transform-limited Gaussian pump, to achieve near-unity spectral purity in heralded single photons at telecommunication wavelength. Theory shows that these phase-matching and pump conditions are sufficient to ensure that a biphoton state with a circularly symmetric joint spectral intensity profile is transform limited and factorable. We verify the heralded- state spectral purity in a four-fold coincidence measurement by performing Hong-Ou-Mandel interference between two independently generated heralded photons. With a mild spectral filter we obtain an interference visibility of 98.4{+or-}1.1% which corresponds to a heralded-state purity of 99.2%. Our heralded photon source is potentially an essential resource for measurement-based quantum information processing and quantum network applications.
Citation
Optics Express
Volume
27

Keywords

quantum interference, indistinguishable photons, spontaneous parametric downconversion
Created April 15, 2019, Updated July 9, 2019