Unphysical metastability of the fundamental Raman soliton in the reduced nonlinear Schroedinger equation

Truong X. Tran; Fabio Biancalana

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arXiv · 1504.03865

Unphysical metastability of the fundamental Raman soliton in the reduced nonlinear Schroedinger equation

Truong X. Tran·Fabio Biancalana

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Abstract

We demonstrate theoretically and numerically that the fundamental Raman soliton of the widely used nonlinear Schroedinger equation (NLSE) with a linear approximation of the Raman gain ({\em reduced} NLSE) is metastable. It can propagate for hundreds of dispersion lengths along the optical fibre before eventually disappearing due to a peculiar instability, leading to a collapse. The noise eigenfunction analysis agrees well with the results obtained via direct pulse propagation simulations. This instability is not present when modelling the Raman effect via a full convolution, and thus the reduced NLSE often leads to unphysical results, and should be avoided.

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Truong X. Tran, Fabio Biancalana. 2015-04-15. Unphysical metastability of the fundamental Raman soliton in the reduced nonlinear Schroedinger equation. https://arxiv.org/abs/1504.03865

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