ABSTRACT Precise measurements of the frequencies of light waves have become common with mode-locked laser frequency combs1. Despite their huge success, optical frequency combs currently

remain bulky and expensive laboratory devices. Integrated photonic microresonators are promising candidates for comb generators in out-of-the-lab applications, with the potential for

reductions in cost, power consumption and size2. Such advances will significantly impact fields ranging from spectroscopy and trace gas sensing3 to astronomy4, communications5 and atomic

time-keeping6,7. Yet, in spite of the remarkable progress shown over recent years8,9,10, microresonator frequency combs (‘microcombs’) have been without the key function of direct _f_–2_f_

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support SIMILAR CONTENT BEING VIEWED BY OTHERS FREQUENCY MICROCOMB STABILIZATION VIA DUAL-MICROWAVE CONTROL Article Open access 22 April 2021 KHZ-PRECISION WAVEMETER BASED ON RECONFIGURABLE

MICROSOLITON Article Open access 12 January 2023 AN INTEGRATED WAVEMETER BASED ON FULLY-STABILIZED RESONANT ELECTRO-OPTIC FREQUENCY COMB Article Open access 16 November 2023 REFERENCES *

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microcavity dispersion. _Nature Photon._ 3, 529–533 (2009). Article  ADS  Google Scholar  Download references ACKNOWLEDGEMENTS This work is supported by the National Institute of Standards

and Technology, the National Physical Laboratory, the California Institute of Technology, the Defense Advanced Research Projects Agency Quantum—Assisted Sensing and Readout programme, the

Air Force Office of Scientific Research and the National Aeronautics and Space Administration. P.D. acknowledges support from the Humboldt Foundation. D.C.C. acknowledges support from the

National Science Foundation Graduate Research Fellowship Program under grant no. DGE 1144083. AUTHOR INFORMATION Author notes * Aurélien Coillet & Hansuek Lee Present address: Present

addresses: Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR CNRS 6303, 9 Avenue Alain Savary, 21078 Dijon, France (A.C.); Graduate School of Nanoscience and Technology, Korea Advanced

Institute of Science and Technology, Daejeon 305-701, South Korea (H.L.), AUTHORS AND AFFILIATIONS * National Physical Laboratory (NPL), Teddington, TW11 0LW, UK Pascal Del'Haye *

National Institute of Standards and Technology (NIST), Boulder, 80305, Colorado, USA Pascal Del'Haye, Aurélien Coillet, Tara Fortier, Katja Beha, Daniel C. Cole, Scott B. Papp & 

Scott A. Diddams * T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, 91125, California, USA Ki Youl Yang, Hansuek Lee & Kerry J. Vahala Authors *

Pascal Del'Haye View author publications You can also search for this author inPubMed Google Scholar * Aurélien Coillet View author publications You can also search for this author

inPubMed Google Scholar * Tara Fortier View author publications You can also search for this author inPubMed Google Scholar * Katja Beha View author publications You can also search for this

author inPubMed Google Scholar * Daniel C. Cole View author publications You can also search for this author inPubMed Google Scholar * Ki Youl Yang View author publications You can also

search for this author inPubMed Google Scholar * Hansuek Lee View author publications You can also search for this author inPubMed Google Scholar * Kerry J. Vahala View author publications

You can also search for this author inPubMed Google Scholar * Scott B. Papp View author publications You can also search for this author inPubMed Google Scholar * Scott A. Diddams View

author publications You can also search for this author inPubMed Google Scholar CONTRIBUTIONS P.D., S.B.P. and S.A.D. conceived the experiments. P.D. and A.C. designed and performed the

experiments. T.F. contributed to the _f_ceo stabilization. K.B. and D.C.C. contributed to the nonlinear spectral broadening. K.Y.Y., H.L. and K.J.V. provided the microresonator. P.D. and

S.A.D. prepared the manuscript, with input from all co-authors. CORRESPONDING AUTHORS Correspondence to Pascal Del'Haye or Scott A. Diddams. ETHICS DECLARATIONS COMPETING INTERESTS The

authors declare no competing financial interests. RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Del'Haye, P., Coillet, A., Fortier, T. _et al._

Phase-coherent microwave-to-optical link with a self-referenced microcomb. _Nature Photon_ 10, 516–520 (2016). https://doi.org/10.1038/nphoton.2016.105 Download citation * Received: 12

January 2016 * Accepted: 27 April 2016 * Published: 06 June 2016 * Issue Date: August 2016 * DOI: https://doi.org/10.1038/nphoton.2016.105 SHARE THIS ARTICLE Anyone you share the following

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