Original Article

Citation: Light: Science & Applications (2017) 6, e16253; doi:10.1038/lsa.2016.253
Published online 21 April 2017

Second-harmonic-assisted four-wave mixing in chip-based microresonator frequency comb generation

Xiaoxiao Xue1,2, François Leo3,4, Yi Xuan2,5, Jose A Jaramillo-Villegas2,6, Pei-Hsun Wang2, Daniel E Leaird2, Miro Erkintalo3, Minghao Qi2,5 and Andrew M Weiner2,5

  1. 1Department of Electronic Engineering, Tsinghua University, Beijing 100084, China
  2. 2School of Electrical and Computer Engineering, Purdue University, 465 Northwestern Avenue, West Lafayette, IN 47907-2035, USA
  3. 3The Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Physics, The University of Auckland, Auckland 1142, New Zealand
  4. 4OPERA-photonics, Université libre de Bruxelles (U.L.B.), 50 Avenue F. D. Roosevelt, CP 194/5, B-1050 Bruxelles, Belgium
  5. 5Birck Nanotechnology Center, Purdue University, 1205 West State Street, West Lafayette, IN 47907, USA
  6. 6Facultad de Ingenierías, Universidad Tecnológica de Pereira, Pereira RIS 660003, Colombia

Correspondence: X Xue, Email: xuexx@tsinghua.edu.cn or xiaoxxue@gmail.com; AM Weiner, Email: amw@purdue.edu

Received 11 August 2016; Revised 1 November 2016; Accepted 11 November 2016
Accepted article preview online 13 November 2016



Simultaneous Kerr comb formation and second-harmonic generation with on-chip microresonators can greatly facilitate comb self-referencing for optical clocks and frequency metrology. Moreover, the presence of both second- and third-order nonlinearities results in complex cavity dynamics that is of high scientific interest but is still far from being well-understood. Here, we demonstrate that the interaction between the fundamental and the second-harmonic waves can provide an entirely new way of phase matching for four-wave mixing in optical microresonators, enabling the generation of optical frequency combs in the normal dispersion regime under conditions where comb creation is ordinarily prohibited. We derive new coupled time-domain mean-field equations and obtain simulation results showing good qualitative agreement with our experimental observations. Our findings provide a novel way of overcoming the dispersion limit for simultaneous Kerr comb formation and second-harmonic generation, which might prove to be especially important in the near-visible to visible range where several atomic transitions commonly used for the stabilization of optical clocks are located and where the large normal material dispersion is likely to dominate.


four-wave mixing; Kerr frequency comb; microresonator; second-harmonic generation