Discrete frequency-bin entanglement generation via cascaded second-order nonlinear processes in Sagnac interferometer

Abstract

Discrete frequency-bin entanglement is an essential resource for applications in quantum information processing. In this Letter, we propose and demonstrate a scheme to generate discrete frequency-bin entanglement with a single piece of periodically poled lithium niobate waveguide in a modified Sagnac interferometer. Correlated two-photon states in both directions of the Sagnac interferometer are generated through cascaded second-order optical nonlinear processes. A relative phase difference between the two states is introduced by changing the polarization state of pump light, thus manipulating the two-photon state at the output of the Sagnac interferometer. The generated two-photon state is sent into a fiber polarization splitter, then a pure discrete frequency-bin entangled two-photon state is obtained by setting the pump light. The frequency entanglement property is measured by a spatial quantum beating with a visibility of $96.0\pm 6.1\%$. The density matrix is further obtained with a fidelity of $98.0\pm 3.0\%$ to the ideal state. Our demonstration provides a promising method for the generation of pure discrete frequency-bin entanglement at telecom band, which is desired in quantum photonics.

arXiv comment4 pages. 3 figures

References in corpus (16)

• The Quantum Internet
• On-chip quantum interference between silicon photon-pair sources
• Entangled photon-pair generation in periodically-poled thin-film lithium niobate waveguides
• Ultra-bright Quantum Photon Sources on Chip
• Discrete, Tunable Color Entanglement
• Frequency Bin Entangled Photons
• Large-Alphabet Time-Frequency Entangled Quantum Key Distribution by means of Time-to-Frequency Conversion
• High-performance source of spectrally pure, polarization entangled photon pairs based on hybrid integrated-bulk optics
• Frequency-bin entanglement from domain-engineered down-conversion
• An all fiber source of frequency entangled photon pairs
• Odd- and even-order dispersion cancellation in quantum interferometry
• Direct generation of frequency-bin entangled photons via two-period quasi-phase-matched parametric downconversion
• Generation of 1.5 μm discrete frequency entangled two-photon state in polarization maintaining fibers
• Highly efficient source for frequency-entangled photon pairs generated in a 3rd order periodically poled MgO-doped stoichiometric LiTaO3 crystal
• Controlled entanglement routing between two virtual pathways
• A polarization maintaining scheme for 1.5 μm polarization entangled photon pair generation in optical fibers

Cited by in corpus (1)

• Polarization-entangled quantum frequency comb from a silicon nitride microring resonator