Abstract
Random lasers are optical sources where light is amplified by stimulated emission along random paths through an amplifying scattering medium. Connections between their physics and the one of quenched disordered nonlinear systems, notably spin glasses, have been recently suggested. Here we report a first experimental study of correlations of spectral fluctuations intensity in a random laser medium where the scatterers displacement significantly changes among consecutive shots. Remarkably, our results reveal that the replica symmetry breaking (RSB) phenomenology is robust with respect to an averaging over different realizations of the disorder. Moreover, besides opening new intriguing questions about the understanding of such a phenomenon, this work aims to clarify the connection between the RSB with the onset of the Lévy regime, i.e. the fluctuations regime that is a peculiar feature of the random lasing under critical conditions. Our results suggest that the former occurs independently of the latter and then the RSB phenomenology is a generic feature linked to the random laser threshold.
Highlights
Of replica symmetry breaking (RSB) in a random laser has been recently reported[32], revealing and underlying non-trivial modes organization and correlation
We report an experimental measurement of the intensity fluctuations overlap, a parameter that has been introduced to demonstrate the symmetry breaking between different replicas in quenched disorder systems
The experimental set-up consists of a pumping system provided by a pulsed laser, a liquid sample for the random laser emission and a synchronized system to collect a large number of spectra
Summary
Of replica symmetry breaking (RSB) in a random laser has been recently reported[32], revealing and underlying non-trivial modes organization and correlation. In presence of RSB, system replicas, i.e. identical realizations under the same experimental conditions, yield different values of the observable parameters. Within this picture, this system is composed by many equivalent degenerate states, with a glassy behaviour[33] that manifests as a thermodynamic phase where the symmetry among different replicas is broken. A second work reported the observation of RSB in a random laser system using strongly scattering solid media (Ls of the order of tens of μm)[36] Such a work investigated the intriguing possibility to find a link between the RSB and the onset of the Lévy regime. We report an experimental measurement of the intensity fluctuations overlap, a parameter that has been introduced to demonstrate the symmetry breaking between different replicas in quenched disorder systems. The RSB transition appears as linked to the random laser threshold, independently on whether the Lévy regime is present or not
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
