4:41 p.m.
Dear Colleagues,
On Friday, September the 16th at 11:30 in Room A1.02 (East Campus, via La Santa 1,
Lugano), Riccardo Meucci will give a talk titled:
40 Years of Chaos in Lasers and its Control
Abstract
We revisit the laser model with cavity loss modulation, from which evidence of chaos and
generalized multistability was discovered in 1982 [1]. Multistability refers to the
coexistence of two or more attractors in nonlinear dynamical systems. Despite its relative
simplicity, the adopted model shows us how the multistability depends on the dissipation
of the system. The model is then tested under the action of a secondary sinusoidal
perturbation, which can remove bistability when a suitable relative phase is chosen [2].
Such a control strategy is universally known as “phase control” and it was first
implemented in the same physical system but at different resonance frequencies [3].
The potential of this control technique has been validated on other paradigmatic chaotic
systems such as the Duffing oscillator. In this particular case, it has been verified that
the control is more sensitive when applied to the cubic term of the nonlinearity [4].
We recently demonstrated that phase control, which is classified as a nonfeedback method,
can be converted to a closed loop control (feedback method) when a suitable adaptive
filter is used on the chaotic signal to be processed [5].
References
[1] F. T. Arecchi, R. Meucci, G. Puccioni, and J. Tredicce, “Experimental evidence of
subharmonic bifurcations, multistability, and turbulence in a Q-switched gas laser,” Phys.
Rev. Lett. 49(17), 1217–1220 (1982).
[2] R. Meucci, J.M. Ginoux, M. Mehrabbeik, S. Jafari, and J. C.Sprott” Generalized
multistability and its control in a laser”: Chaos 32, 083111 (2022); doi:
10.1063/5.0093727.
[3] Meucci, W. Gadomski, M. Ciofini, and F. T. Arecchi, “Experimental control of chaos by
means of weak parametric perturbations,” Phys. Rev. E 49(4), R2528–R2531 (1994).
[4] R. Meucci, S. Euzzor, E. Pugliese, S. Zambrano, M. R. Gallas, and J. A. C. Gallas,
“Optimal phase-control strategy for damped-driven Duffing oscillators,” Phys. Rev. Lett.
116(4), 044101 (2016).
[5] R. Meucci, S. Euzzor, M.Ciofini, A.Lapucci, and S. Zambrano” Demonstrating Filtered
Feedback Control Near a Boundary Crisis” IEEE Trans. on Circuits and Systems¬ -I: 68(7),
3023 (2021).
The speaker
Riccardo Meucci received the doctor degree in Physics in 1982 and the specialization
degree in Optics (PhD), both from University of Florence, Italy. From 1984 to 1987, he was
research fellow at the Istituto di Cibernetica of the National Research Council (CNR) of
Italy. Since 1987, he joined with the National Institute of Optics, Firenze, Italy, where
he holds the position of Research Director. He is also contract professor of physical
optics and mathematical methods for optics at University of Firenze. Riccardo Meucci is
associate editor for the International Journal of Bifurcation and Chaos (IJBC) from 1
January 2018.
His research interests include nonlinear dynamics, chaos, control of chaos,
synchronization and infrared digital holography.
He is IEEE Senior Member since 17 November 2018.