1,074 research outputs found
Quantitative analysis of several random lasers
We prescribe the minimal set of experimental data and parameters that should
be reported for random-laser experiments and models. This prescript allows for
a quantitative comparison between different experiments, and for a criterion
whether a model predicts the outcome of an experiment correctly. In none of
more than 150 papers on random lasers that we found these requirements were
fulfilled. We have nevertheless been able to analyze a number of published
experimental results and recent experiments of our own. Using our method we
determined that the most intriguing property of the random laser (spikes) is in
fact remarkably similar for different random lasers.Comment: 3 pages, 1 figur
Glassy behavior of light
We study the nonlinear dynamics of a multi-mode random laser using the
methods of statistical physics of disordered systems. A replica-symmetry
breaking phase transition is predicted as a function of the pump intensity. We
thus show that light propagating in a random non-linear medium displays glassy
behavior, i.e. the photon gas has a multitude of metastable states and a non
vanishing complexity, corresponding to mode-locking processes in random lasers.
The present work reveals the existence of new physical phenomena, and
demonstrates how nonlinear optics and random lasers can be a benchmark for the
modern theory of complex systems and glasses.Comment: 5 pages, 1 figur
Glassy behavior of light in random lasers
A theoretical analysis [Angelani et al., Phys. Rev. Lett. 96, 065702 (2006)]
predicts glassy behaviour of light in a nonlinear random medium. This implies
slow dynamics related to the presence of many metastable states. We consider
very general equations (that also apply to other systems, like Bose-Condensed
gases) describing light in a disordered non-linear medium and through some
approximations we relate them to a mean-field spin-glass-like model. The model
is solved by the replica method, and replica-symmetry breaking phase transition
is predicted. The transition describes a mode-locking process in which the
phases of the modes are locked to random (history and sample-dependent) values.
The results are based on very general theory, and embrace a variety of physical
phenomena.Comment: 21 pages, 3 figures. Revised and enlarged version. To be published in
Physical Review
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