Correlated twin-photon generation in a silicon nitrite loaded thin film PPLN waveguide

TL;DR

This paper demonstrates a silicon nitride loaded thin film periodically poled lithium niobate waveguide as a source of correlated twin-photon pairs suitable for quantum information processing, with high brightness and telecom compatibility.

Contribution

It introduces a novel integrated photon-pair source using silicon nitride and lithium niobate, achieving high brightness and telecom wavelength compatibility.

Findings

Photon pairs centered at 1560 nm with 21 THz bandwidth

High cross-correlation g^{(2)}(0) of about 8000

Heralded single photon emission with g^{(2)}_H(0) ≈ 0.04

Abstract

Photon-pair sources based on thin film lithium niobate on insulator technology have a great potential for integrated optical quantum information processing. We report on such a source of correlated twin-photon pairs generated by spontaneous parametric down conversion in a silicon nitride (SiN) rib loaded thin film periodically poled lithium niobate (LN) waveguide. The generated photon pairs have a wavelength centred at 1560\,nm compatible with present telecom infrastructure, a large bandwidth (21\,THz) and a brightness of $\sim 2.5\times 10^5$\,pairs/s/mW/GHz. The photons are correlated and exhibit a cross correlation $g^{(2)}(0)$ of about 8000. Using the Hanbury Brown and Twiss effect, we have also shown heralded single photon emission, achieving an autocorrelation $g^{(2)}_H(0) \simeq 0.04$.