On-Chip Generation and Manipulation of Entangled Photons Based on Reconfigurable Lithium-Niobate Waveguide Circuits

TLDR

A trend toward high‑performance quantum information processing drives the development of fully integrated photonic chips. The authors report on‑chip generation and manipulation of entangled photons using reconfigurable lithium‑niobate waveguide circuits. The chip incorporates a periodically poled lithium‑niobate waveguide with electro‑optic phase control to produce two photon‑pair sources inside a Hong‑Ou‑Mandel interferometer, and nine identical units are arranged to generate identical photon pairs across the telecom C and L bands via flexible nonlinearity engineering. The device achieves 92.9 ± 0.9 % Hong‑Ou‑Mandel visibility, a photon flux of ~1.4 × 10^7 pairs nm^−1 mW^−1, and demonstrates a scalable on‑chip platform for engineering diverse photon sources, paving the way toward fully integrated quantum technologies.

Abstract

A consequent tendency toward high-performance quantum information processing is to develop the fully integrated photonic chip. Here, we report the on-chip generation and manipulation of entangled photons based on reconfigurable lithium-niobate waveguide circuits. By introducing a periodically poled structure into the waveguide circuits, two individual photon-pair sources with a controllable electro-optic phase shift are produced within a Hong-Ou-Mandel interferometer, resulting in a deterministically separated identical photon pair. The state is characterized by 92.9±0.9% visibility Hong-Ou-Mandel interference. The photon flux reaches ∼1.4×10(7) pairs nm-1 mW-1. The whole chip is designed to contain nine similar units to produce identical photon pairs spanning the telecom C and L band by the flexible engineering of nonlinearity. Our work presents a scenario for on-chip engineering of different photon sources and paves the way to fully integrated quantum technologies.