16,285 research outputs found
Chess-Board-Like Spatio-Temporal Interference Patterns and Their Excitation
We discover new type of interference patterns generated in the focusing
nonlinear Schr\"odinger equation (NLSE) with localised periodic initial
conditions. At special conditions, found in the present work, these patterns
exhibit novel chess-board-like spatio-temporal structures which can be observed
as the outcome of collision of two breathers. The infinitely extended
chess-board-like patterns correspond to the continuous spectrum bands of the
NLSE theory. More complicated patterns can be observed when the initial
condition contains several localised periodic swells. These patterns can be
observed in a variety of physical situations ranging from optics and
hydrodynamics to Bose-Einstein condensates and plasma.Comment: 6 pages, 5 figure
Characteristics of optical multi-peak solitons induced by higher-order effects in an erbium-doped fiber system
We study multi-peak solitons \textit{on a plane-wave background} in an
erbium-doped fiber system with some higher-order effects, which is governed by
a coupled Hirota and Maxwel-Bloch (H-MB) model. The important characteristics
of multi-peak solitons induced by the higher-order effects, such as the
velocity changes, localization or periodicity attenuation, and state
transitions, are revealed in detail. In particular, our results demonstrate
explicitly that a multi-peak soliton can be converted to an anti-dark soliton
when the periodicity vanishes; on the other hand, a multi-peak soliton is
transformed to a periodic wave when the localization vanishes. Numerical
simulations are performed to confirm the propagation stability of multi-peak
solitons riding on a plane-wave background. Finally, we compare and discuss the
similarity and difference of multi-peak solitons in special degenerate cases of
the H-MB system with general existence conditions.Comment: 7 pages, 4 figure
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