Laser Cavity Solitons in Microresonators Self-Emergence

Alessia Pasquazi

Emergent Photonics Research Centre and Dept. of Physics, Loughborough University, Loughborough, LE11 3TU, England, UK -
M. Rowley, P-H Hanzard, A. Cutrona, L. Olivieri, L. Peters, D. Das, H. Bao, S. T. Chu, B. E. Little, R. Morandotti, D. J. Moss, G.-L. Oppo, J.S. Totero Gongora, M. Peccianti and Alessia Pasquazi

In many disciplines, states that emerge in open systems far from equilibrium are determined by a few global parameters1,2. These states can often mimic thermodynamic equilibrium, and a classic example of this is the oscillation threshold of a laser3, which resembles a phase transition in condensed matter. However, many relevant classes of states cannot form spontaneously in dissipative systems, and this is the case for cavity-solitons2 . These types of states have been largely investigated in spatial systems and generally need to be induced by external perturbations, as in the case of optical memories4. In the last decade, these highly localised states have enabled significant advancements in microresonator-based optical frequency combs5. Critically, the very advantages that make cavity-solitons attractive for memories – their inability to form spontaneously from noise – have created fundamental challenges in the field of microcombs. To be reliable sources, microcombs require the essential features of starting laser oscillation naturally, spontaneously and reliably, and operating in a desired, intrinsically robust state. Largely because of the intrinsic nature of cavity-solitons, these goals have remained elusive. Here, we show that slow nonlinearities of a free-running microresonator-filtered fibre laser6 can transform temporal cavity-solitons into the dominant attractor of the system7. This phenomenon leads to reliable self-starting oscillation of cavity-solitons in microresonatiors that, in addition, are naturally robust to perturbations, recovering spontaneously even after a complete disruption.

  1. Nicolis & Prigogine, Self-Organization in Nonequilibrium Systems (1977).
  2. Lugiato et al., Nonlinear optical systems (2015).
  3. DeGiorgio & Scully Phys. Rev. A 2, 1170 (1970).
  4. Barland. et al. Nature 419, 699 (2002).
  5. Kippenberg et al. Science 361, eaan8083 (2018).
  6. Bao et al. Nat. Photonics 13, 384 (2019).
  7. Rowley et al. 10.1038/s41586-022-04957-x (2022).

Professor Alessia Pasquazi (PhD 2009 in Electronic Engineering University ‘Roma Tre’) is an expert in nonlinear optics, she is fascinated by how light interacts with light, mimicking often living systems. Her focus is on applying such a physics to practical ultrafast photonic technologies and she is a relevant expert in the field of microcombs. She has been MELS fellow (Quebec, Canada) from 2010-2011 and EU Marie-Curie Fellow from 2013-2015, Ernest Rutherford Fellow (2018-2023), ERC Starting Grant Laureate (2020-2024). She has joined Loughborough in 2022 from the University of Sussex where she was Co-Director of the Emergent Photonics laboratory.