Polarization-entangled photon pairs generation from a single lithium niobate waveguide with single poling period

TL;DR

This paper presents a simple, scalable method for generating polarization-entangled photon pairs with large detuning using a single-period poled thin-film lithium niobate waveguide, advancing integrated quantum photonics.

Contribution

It introduces a novel, efficient scheme leveraging type-0 SPDC in a single-period poled waveguide for entangled photon generation with on-chip temporal compensation.

Findings

Achieved generation of both degenerate and highly detuned entangled photon pairs.

Demonstrated on-chip temporal compensation for improved entanglement quality.

Proposed a compact, scalable platform suitable for integrated quantum photonic circuits.

Abstract

Polarization-entangled photon pairs are essential sources for photonic quantum information processing. However, generating entangled photon pairs with large detuning via spontaneous parametric down-conversion (SPDC) often requires complex configurations to compensate for phase matching. Here, we propose a simple and efficient scheme to generate polarization-entangled photon pairs based on type-0 SPDC in a thin-film lithium niobate waveguide with a single poling period. By utilizing the strong dispersion engineering capabilities of thin-film waveguides, we can achieve both degenerate and highly detuned entangled photon pairs. Furthermore, we demonstrate on-chip temporal compensation using an integrated waveguide structure. Our approach offers a compact and scalable solution for integrated quantum photonic circuits.