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Updated: Jun 10, 2026

Measurement of Quantum Interference in a Silicon Ring Resonator Photon Source
Published on: April 4, 2017
Two-photon quantum interference and entanglement at 2.1 μm
Shashi Prabhakar1, Taylor Shields1, Adetunmise C Dada1
1James Watt School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK.
Abstract:
Quantum-enhanced optical systems operating within the 2- to 2.5-μm spectral region have the potential to revolutionize emerging applications in communications, sensing, and metrology. However, to date, sources of entangled photons have been realized mainly in the near-infrared 700- to 1550-nm spectral window. Here, using custom-designed lithium niobate crystals for spontaneous parametric down-conversion and tailored superconducting nanowire single-photon detectors, we demonstrate two-photon interference and polarization-entangled photon pairs at 2090 nm. These results open the 2- to 2.5-μm mid-infrared window for the development of optical quantum technologies such as quantum key distribution in next-generation mid-infrared fiber communication systems and future Earth-to-satellite communications.
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