Introduction

“Kia ora koutou katoa”

The WALL-IN project (confining walls-of-Light in nonlinear Kerr resonators) is an International Research Project focused on the study of nonlinear dynamics occurring in optical Kerr resonators. This project is managed by Julien Fatome from the Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB) in Dijon (France) in collaboration with the photonics group of The University of Auckland (New-Zealand).

Research activities

Optical frequency combs (OFCs) are made of thousands of discrete and evenly spaced frequency lines. They can act as “spectral optical rulers” that enable to measure unknown optical frequencies with extraordinarily high precision and for which its inventors were awarded by the Nobel prize in 2005. Frequency comb systems commercially available mainly rely on bulky ultrashort-pulse lasers and supercontinuum technologies. However, a fundamentally different approach was demonstrated in 2007, when continuous laser light was shown to be transformed into an evenly-spaced comb when confined into a nonlinear Kerr microresonator. It is now well understood that such OFC generation in Kerr resonators is mostly based on the emergence of robust, short and bright temporal structures, called dissipative cavity solitons (CSs). First observed in a macroscale optical fiber ring, CSs have attracted growing interest over the past decade and have led to major advances in numerous fields of science such as massively multiplexed optical telecommunications, optical buffering, lidar systems, astrocombs or spectroscopy for molecular fingerprinting. However, CSs are mostly restricted to optical platforms characterized by anomalous chromatic dispersion, which dramatically limits the range of available spectral bands and thus potential applications. Indeed, recalling that numerous materials are characterized by strong normal dispersion, in particular in the mid-infrared where molecules provide strong absorptions, there is a growing interest in the generation of short temporal structures in normally dispersive Kerr resonators so as to extend the applications of OFCs to new spectral regions. So far, several different strategies have been reported such as dark optical solitons, locking of switching waves, platicons or mode coupling in microresonators. However, generation of broad OFCs in normal dispersion regime is still an opened question. In the framework of the Wall-IN project, we combine the complementary expertise of two leading groups of the nonlinear fiber optics community (ICB laboratory in Dijon and The University of Auckland) to extend the applications of OFCs and associated dissipative temporal structures in normal dispersion Kerr resonators around 1.55 µm. Our strategy is based on the investigation of novel vectorial and multimode nonlinear dynamics in fiber-based macro-resonators which are known to be governed by the same equations than microresonators, whist providing much easier and versatile experimental implementation. Subsequently, our findings will be investigated within micro-fiber loops and finally in integrated Kerr microresonators.

A fruitful collaboration

The collaboration between the ICB laboratory and The University of Auckland is focused on the international hot-topic dealing with cavity solitons and optical frequency combs generation in nonlinear Kerr resonators. This collaboration benefits from the complementary and strong expertise of the two groups in nonlinear fiber optics, temporal cavity solitons (UoA) and all-optical polarization control (ICB). In that context, our collaboration has been strongly reinforced by 3 academic stays of J. Fatome at UoA in 2015, 2017 and 2020. This collaborative activity dealing with cavity solitons and optical frequency combs generation has already been awarded by several common scientific contributions.

List of publications

1. J. Fatome, F. Leo, M. Guasoni, B. Kibler, M. Erkintalo, and S. Coen “Polarization domain-wall cavity solitons in isotropic fiber ring resonators,” in Nonlinear Photonics conference, paper NW3B.6 (2016).
2. Y. Wang, F. Leo, J. Fatome, M. Erkintalo, S. G. Murdoch and S. Coen “Universal mechanism for the binding of temporal cavity solitons,” Optica 4, 855-863 (2017).
3. J. Fatome, Y. Wang, B. Garbin, B. Kibler, A. Bendahmane, N. Berti, G.-L. Oppo, F. Leo, S. G. Murdoch, M. Erkintalo, and S. Coen “Flip-flop polarization domain walls in a Kerr resonator,” in Advanced Photonics Congress, post-deadline paper JTu6F.2 (2018).
4. B. Garbin, J. Fatome, Y. Wang, A. Bendahmane, G. L. Oppo, S. G. Murdoch, M. Erkintalo and S. Coen “Symmetry breaking and polarization domain walls in a passive resonator,” in SPIE Photonics West conference, 10517 (2018).
5. J. Fatome, N. Berti, B. Kibler, B. Garbin, S. G. Murdoch, M. Erkintalo and S. Coen “Temporal Tweezing of Polarization Domain Walls in a Fiber Kerr Resonator,” in CLEO US, paper SW3H.3 (2019).
6. J. Nuño, C. Finot, G. Xu, G. Millot, M. Erkintalo and J. Fatome “Vectorial dispersive shock waves in optical fibers,” Communications Physics 2, 138 (2019).
7. S. Coen, B. Garbin, J. Fatome, Y. Wang, F. Leo, G. L. Oppo, S. G. Murdoch, and M. Erkintalo “Dissipative polarization domain walls as persisting topological defects,” in CLEO Pacific Rim, invited contribution, paper Th4B.1 (2018).
8. B. Garbin, J. Fatome, G.-L. Oppo, M. Erkintalo, S. G. Murdoch, and S. Coen “Asymmetric balance in symmetry breaking,” Phys. Rev. Research 2, 023244 (2020).
9. J. Fatome, M. Erkintalo, S. G. Murdoch, and S. Coen “Polarization faticon in normally dispersive Kerr resonators,” in Advanced Photonics Congress, paper NpW2E.8 (2020).
10. J. Fatome, B. Kibler, F. Leo, A. Bendahmane, G.-L. Oppo, B. Garbin, Y. Wang, S. G. Murdoch, M. Erkintalo, and S. Coen “Polarization modulation instability in a nonlinear fiber Kerr resonator,” Optics Letters 45, 5069-5072 (2020).
11. B. Garbin, J. Fatome, G.-L. Oppo, M. Erkintalo, S. G. Murdoch, and S. Coen “Dissipative polarization domain walls in a passive driven Kerr resonator,” Phys. Rev. Lett. 126, 023904 (2021).
12. G. Xu, A. Nielsen, B. Garbin, J. Fatome, L. Hill, G.-L. Oppo, S. Coen, S. G. Murdoch, and M. Erkintalo, “Spontaneous symmetry breaking of dissipative solitons in a two-component Kerr resonator,” Nature Communications 12, 4023 (2021).
13. Y. Xu, A. Sharples, J. Fatome, S. Coen, M. Erkintalo and S. G. Murdoch “Frequency comb generation in a pulse-pumped normal dispersion Kerr mini-resonator,” Optics Letters 46, 512-515 (2021).
14. Y. Xu, A. Sharples, J. Fatome, S. Coen, M. Erkintalo and S. G. Murdoch, “Tunable Kerr combs in a normal dispersion pulse-driven mini-resonator,” in CLEO US, paper FTu4E (2021).
15. J. Fatome, G. Xu, B. Garbin, N. Berti, G.-L. Oppo, S. G. Murdoch, M. Erkintalo, and S. Coen “Universal flip-flopping and self-symmetrization of symmetry-breaking dynamics in passive Kerr resonators,” in CLEO US, paper FM4H (2021).
16. J. Fatome, G. Xu, B. Garbin, N. Berti, G.-L. Oppo, S. G. Murdoch, M. Erkintalo, and S. Coen “Self-symmetrization of two-component cavity solitons in coherently driven passive Kerr resonators,” in CLEO Europe, paper EF-P.1 (2021).
17. G. Xu, A. Nielsen, B. Garbin, L. Hill, G.-L. Oppo, J. Fatome, S. G. Murdoch, S. Coen and M. Erkintalo “Features of spontaneous symmetry breaking of dissipative cavity solitons in passive Kerr resonators“, in CLEO Europe, paper EF-5.4 (2021).
18. N. Englebert, S.-P. Gorza, F. Leo, M. Erkintalo and J. Fatome, “Observation of temporal cavity solitons in a synthetic photonic lattice,” in CLEO Europe, postdeadline paper PD-2.7 (2021).
19. J. Fatome, G. Xu, B. Garbin, N. Berti, G.-L. Oppo, S. G. Murdoch, M. Erkintalo and S. Coen, “Self-symmetrization of symmetry-breaking dynamics in passive Kerr resonators,” arXiv:2106.07642 (2021).
20.  G. Xu, L. Hill, J. Fatome, G.-L. Oppo, M. Erkintalo, S. G. Murdoch and S. Coen, “Breathing dynamics of symmetry-broken temporal cavity solitons in Kerr ring resonators,” Opt. Lett. 47, 1486-1489 (2022
21. J. Fatome, “Self-symmetrization of spontaneous symmetry-breaking in driven Kerr resonators,” workshop on Frequency combs, Fundamentals & Applications, invited conference, Brussels, 12-13 Sept. (2022).
22. N. Berti, S. Coen, M. Erkintalo and J. Fatome “Extreme time-multiplexing of optical data packets through ultrafast temporal focusing“, postdeadline paper JTh4A.1, Advanced Photonics Congress,  Maastricht, July (2022).
23.  N. Berti, S. Coen, M. Erkintalo and J. Fatome, “Extreme waveform compression with a nonlinear temporal focusing mirror,” Nature Photonics 16, 822-827 (2022)
24.  N. Englebert, N. Goldman, M. Erkintalo, N. Mostaan, S-P. Gorza, F. Leo and J. Fatome “Bloch oscillations of coherently driven dissipative solitons in a synthetic dimension,” Nat. Phys. 19, 1014–1021 (2023)
25.  J. Fatome, E. Lucas, B. Kibler, L. Hill, G.-L. Oppo, G. Xu, S. G. Murdoch, M. Erkintalo and S. Coen “Observation of polarization Faticons in a fibre Kerr resonator,” CLEO Europe, postdeadline paper pd_2_7 (2023).
26.  J. Fatome, N. Berti, B. Kibler, G. Xu, S. G. Murdoch, M. Erkintalo, S. Coen, “Temporal manipulation of period-2 polarization domain wall solitons in a nonlinear fiber Kerr resonator,” Optics Communications, 548,129810 (2023).
27. S. Coen, B. Garbin, G. Xu, L. Quinn, N. Goldman, G.-L. Oppo, M. Erkintalo, S. G. Murdoch and J. Fatome “Nonlinear topological symmetry protection in a dissipative system,” Nat. Commun. 15, 1398 (2024).
28. G. Moille, M. Leonhardt, D. Paligora, N. Englebert, F. Leo, J. Fatome, K. Srinivasan and M. Erkintalo, “Parametrically driven pure-Kerr temporal solitons in a chip-integrated microcavity,” Nat. Photon. (2024).

Laboratories and members involved

France

• Julien Fatome, ICB UMR 6303 CNRS-Université de Bourgogne
• Bertrand Kibler, ICB UMR 6303 CNRS-Université de Bourgogne
• Kamal Hammani, ICB UMR 6303 CNRS-Université de Bourgogne
• Guy Millot, ICB UMR 6303 CNRS-Université de Bourgogne

New Zealand

• Stephane Coen, The University of Auckland
• Miro Erkintalo, The University of Auckland
• Stuart G. Murdoch, The University of Auckland

We are always opened to new collaborations and regularly provide new positions for students and postdocs, don’t hesitate to contact us!

Schematic illustration of optical frequency combs generation in normally dispersive Kerr resonators by harnessing vectorial nonlinear interactions. CW: Continuous Wave.

Picture of the UoA group with French visitors [J. Fatome (ICB), S. Barland (Inphyni) and G. Tissoni (Inphyni)]

Transmission of an Argon laser light beam in an optical fiber (credit J. Fatome & S. Pitois) read the news