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Temporal fluctuations of waves in weakly nonlinear disordered media

S. E. Skipetrov
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Abstract

We consider the multiple scattering of a scalar wave in a disordered medium with a weak nonlinearity of Kerr type. The perturbation theory, developed to calculate the temporal autocorrelation function of scattered wave, fails at short correlation times. A self-consistent calculation shows that for nonlinearities exceeding a certain threshold value, the multiple-scattering speckle pattern becomes unstable and exhibits spontaneous fluctuations even in the absence of scatterer motion. The instability is due to a distributed feedback in the system "coherent wave + nonlinear disordered medium". The feedback is provided by the multiple scattering. The development of instability is independent of the sign of nonlinearity.

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S. E. Skipetrov. 2001-01-05. Temporal fluctuations of waves in weakly nonlinear disordered media. https://doi.org/10.1103/physreve.63.056614

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