ABSTRACT Photon pair sources are fundamental building blocks for quantum entanglement and quantum communication. Recent studies in silicon photonics have documented promising characteristics

for photon pair sources within the telecommunications band, including sub-milliwatt optical pump power, high spectral brightness and high photon purity. However, most quantum systems

suitable for local operations, such as storage and computation, support optical transitions in the visible or short near-infrared bands. In comparison to telecommunications wavelengths, the

higher optical attenuation in silica at such wavelengths limits the length scale over which optical-fibre-based quantum communication between such local nodes can take place. One approach to

nitride resonators to generate narrow-band photon pairs with unprecedented purity and brightness, with a coincidence-to-accidental ratio up to 3,780 ± 140 and a detected photon pair flux up

to (18,400 ± 1,000) pairs s−1. We further demonstrate visible–telecom time–energy entanglement and its distribution over a 20 km fibre, far exceeding the fibre length over which purely

visible wavelength quantum light sources can be efficiently transmitted. Finally, we show how dispersion engineering of the microresonators enables the connections of different species of

trapped atoms/ions, defect centres and quantum dots to the telecommunications bands for future quantum communication systems. Access through your institution Buy or subscribe This is a

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* Log in * Learn about institutional subscriptions * Read our FAQs * Contact customer support SIMILAR CONTENT BEING VIEWED BY OTHERS COHERENT LIGHT SCATTERING FROM A TELECOM C-BAND QUANTUM

DOT Article Open access 15 December 2023 SPIN-PHOTON ENTANGLEMENT WITH DIRECT PHOTON EMISSION IN THE TELECOM C-BAND Article Open access 11 November 2024 A HYBRID INTEGRATED QUANTUM KEY

DISTRIBUTION TRANSCEIVER CHIP Article Open access 06 September 2023 DATA AVAILABILITY The data that supports the plots within this paper and other findings of this study are available from

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  Google Scholar  Download references ACKNOWLEDGEMENTS X.L., Q.L., G.M. and A.S. acknowledge support under the Cooperative Research Agreement between the University of Maryland and

NIST-CNST, award number 70NANB10H193. AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Microsystems and Nanotechnology Division, Physical Measurement Laboratory, National Institute of Standards

and Technology, Gaithersburg, MD, USA Xiyuan Lu, Qing Li, Daron A. Westly, Gregory Moille, Anshuman Singh & Kartik Srinivasan * Maryland NanoCenter, University of Maryland, College

Park, MD, USA Xiyuan Lu, Qing Li, Gregory Moille & Anshuman Singh * Photon Spot, Inc, Monrovia, CA, USA Vikas Anant Authors * Xiyuan Lu View author publications You can also search for

this author inPubMed Google Scholar * Qing Li View author publications You can also search for this author inPubMed Google Scholar * Daron A. Westly View author publications You can also

search for this author inPubMed Google Scholar * Gregory Moille View author publications You can also search for this author inPubMed Google Scholar * Anshuman Singh View author publications

You can also search for this author inPubMed Google Scholar * Vikas Anant View author publications You can also search for this author inPubMed Google Scholar * Kartik Srinivasan View

author publications You can also search for this author inPubMed Google Scholar CONTRIBUTIONS X.L. led the design, fabrication and measurement of the entangled photon pair source devices.

Q.L., A.S., G.M. and K.S. provided assistance with design and measurement. D.A.W. provided assistance with fabrication and V.A. contributed experimental tools. X.L. and K.S. wrote the

manuscript. K.S. supervised the project. CORRESPONDING AUTHORS Correspondence to Xiyuan Lu or Kartik Srinivasan. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing

interests. ADDITIONAL INFORMATION JOURNAL PEER REVIEW INFORMATION: _Nature Physics_ thanks Anthony Laing and other anonymous reviewers for their contribution to the peer review of this work.

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Supplementary Sections 1–4 and Supplementary Figures 1–4. RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Lu, X., Li, Q., Westly, D.A. _et al._

Chip-integrated visible–telecom entangled photon pair source for quantum communication. _Nat. Phys._ 15, 373–381 (2019). https://doi.org/10.1038/s41567-018-0394-3 Download citation *

Received: 30 May 2018 * Accepted: 03 December 2018 * Published: 21 January 2019 * Issue Date: April 2019 * DOI: https://doi.org/10.1038/s41567-018-0394-3 SHARE THIS ARTICLE Anyone you share

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