The webinar starts with the model introduced by Luigi Lugiato and Renè Lefever in 1987 (LLE), with the aim of formulating a paradigm for optical pattern formation. Even if this conception was of a purely theoretical nature and the LLE was based on rather idealized conditions, it turned out to be visionary in connection with the discovery of broadband Kerr frequency combs in driven microresonators of very high-Q filled with a Kerr medium, a result attained by Kippenberg and collaborators twenty years after the introduction of the LLE. Combined with the ability to miniaturize and integrate on-chip, soliton Kerr frequency combs have already found several applications and are promising for the future of nonlinear photonics.

Recently, soliton frequency combs have also been observed in quantum cascade lasers, an important class of lasers introduced by Federico Capasso and collaborators in 1994, near the threshold. These combs are well described by the extension of the LLE formulated in 2008. The webinar discusses a generalized LLE that is capable of describing frequency combs both in passive systems without population inversion and in lasers, and the very recent experiments conducted in quantum cascade lasers driven by an external coherent field. This enables repeatable turnkey generation of bright solitons that remains robust for hours of continuous generation.

Finally, the webinar will discuss soliton frequency combs also in a paradigmatic model of laser with saturable absorber. The webinar mostly concerns semiclassical theory, but will discuss also some relevant quantum aspects of Kerr frequency comb

Subject Matter Level: Introductory - Assumes little previous knowledge of the topic

What You Will Learn:
• You will learn about soliton frequency combs both in passive systems and in lasers, including both theoretical and experimental aspects and the applicative perspectives of such investigations.

Who Should Attend:
• PhD students and researchers.

About the Presenter: Luigi Lugiato from The University of Insubria

Luigi Lugiato, born December 17, 1944, is an esteemed Italian physicist and professor emeritus at the University of Insubria (Varese/Como). Renowned for his groundbreaking contributions to theoretical nonlinear and quantum optics, Lugiato is celebrated for nco-formulating the Lugiato-Lefever equation (LLE). With over 340 scientific articles and a seminal textbook. on Nonlinear Dynamical Systems to his credit, he has profoundly influenced both theoretical and experimental realms. His research seamlessly integrates classical and quantum aspects of optical systems, elucidating phenomena such as bistability, cavity solutions, and Kerr frequency combs. Lugiato's seminal work has garnered international recognition, including prestigious honors like the Albert A. Michelson Medal, the Wills E. Lamb Medal, and the Quantum Electronics Award. As a Fellow of multiple esteemed scientific societies, his legacy continues to inspire generations of physicists worldwide.