Generation and characterization of ultrabroadband polarization–frequency hyperentangled photons

作者：Hsuan‐Hao Lu, Muneer Alshowkan, Karthik V. Myilswamy, Andrew M. Weiner, Joseph M. Lukens, Nicholas A. Peters · 发表于：Optics Letters · 年份：2023 · DOI：10.1364/ol.503127 · 被引用次数：30 · 研究领域：Quantum Information and Cryptography、Quantum optics and atomic interactions、Neural Networks and Reservoir Computing

We generate ultrabroadband photon pairs entangled in both polarization and frequency bins through an all-waveguided Sagnac source covering the entire optical C- and L-bands (1530-1625 nm). We perform comprehensive characterization of high-fidelity states in multiple dense wavelength-division multiplexed channels, achieving full tomography of effective four-qubit systems. Additionally, leveraging the inherent high dimensionality of frequency encoding and our electro-optic measurement approach, we demonstrate the scalability of our system to higher dimensions, reconstructing states in a 36-dimensional Hilbert space consisting of two polarization qubits and two frequency-bin qutrits. Our findings hold potential significance for quantum networking, particularly dense coding and entanglement distillation in wavelength-multiplexed quantum networks.