NONLINEAR DYNAMICS IN OPTICS: PRESENT AND NEW PERSPECTIVES

Florence
July 20, 2022
 

17th SICC International Tutorial Workshop "Topics in nonlinear dynamics"
Nonlinear Dynamics in Optics:
Present and new Perspectives

Florence, Galileo Galilei Institute for Theoretical Physics

July 20, 2022

program

Wednesday, July 20

14:00-14.15 Registration of the participants
14-15-14:30 Opening
14:30-15:15 Francesco Marino
Analogue spatiotemporal phenomena in long-delayed systems
15:15-16:00 Cristian Masoller
Time-crystal-oscillations in the output of a weakly modulated semiconductor laser with optical feedback near threshold
16:00-16:30 Coffee break
16:30-17:15 Gian Luca Lippi
An elusive critical phenomenon: laser threshold as a function of system size
17:15-18:00 Round table
 
18:00-18:45 Social event
 

 

Abstracts of the contributions

Francesco Marino

INO- CNR, Florence, Italy

Analogue spatiotemporal phenomena in long-delayed systems

When the delay is much longer than any other characteristic timescale, the data generated by a delayed system can be mapped into an equivalent spatiotemporal representation, in which the involved multiple timescales act as mutually independent spatial and temporal variables. This approach had considerable success, as the complex dynamics in the time-domain often results into simpler spatiotemporal patterns in the new representation. I discuss a general framework for the treatment of long-delayed systems in terms of partial differential equations in the thermodynamic limit, and present results from a series of experiments based on semiconductor lasers with long-delayed optoelectronic feedback. A variety of analogue spatiotemporal phenomena are shown to emerge depending on the local dynamics of the system, including domain coarsening and nucleation, front pinning and localized structures, critical phase-transitions and, more recently, excitable waves segments.


Cristina Masoller

Universitat Politécnica de Catalunya (UPC), Barcelona, Spain

Time-crystal-oscillations in the output of a weakly modulated semiconductor laser with optical feedback near threshold

Time crystal oscillations in interacting, periodically-driven disordered systems are highly regular oscillations that persist for long periods of time, are robust to perturbations, and whose frequency differs from the frequency of the driving signal [Yao and Nayak, 2018].
We demonstrate experimentally that a weak modulation of the laser current induces, near threshold and for particular modulation conditions, long-range regularity in the intensity dynamics. With pulsed modulation we found harmonic and subharmonically locking, while with sinusoidal modulation, we found only subharmonic locking, which is interpreted as time-crystal behavior [Tiana-Alsina and Masoller, 2022].


Gian Luca Lippi

Université Côte d'Azur, Nice, France

An elusive critical phenomenon: laser threshold as a function of system size

TO BE DEFINED.