Entangled photon-pair generation in periodically-poled thin-film lithium niobate waveguides

TL;DR

This paper demonstrates high-quality entangled photon pairs and heralded single photons generated in periodically-poled lithium niobate on insulator waveguides at telecommunications wavelengths, with high brightness and interference visibility.

Contribution

It reports the first measurements of time-frequency entangled photon pairs and heralded single photons in LNOI waveguides with high performance metrics.

Findings

High Coincidences-to-Accidentals Ratio (CAR) achieved

Low conditional self-correlation function [$g^{(2)}$(0)]

High two-photon energy-time Franson interferometric visibility

Abstract

We report measurements of time-frequency entangled photon pairs and heralded single photons at telecommunications wavelengths, generated using a periodically-poled, lithium niobate on insulator (LNOI) waveguide pumped optically by a diode laser. We achieve a high Coincidences-to-Accidentals Ratio (CAR) at high pair brightness, a low value of the conditional self-correlation function [$g^{(2)}$(0)], and high two-photon energy-time Franson interferometric visibility, which demonstrate the high quality of the entangled photon pairs and heralded single photons.