3 research outputs found
Stability Analysis of Continuous Waves in Nonlocal Random Nonlinear Media
On the basis of the competing cubic-quintic nonlinearity model, stability
(instability) of continuous waves in nonlocal random non-Kerr nonlinear media
is studied analytically and numerically. Fluctuating media parameters are
modeled by the Gaussian white noise. It is shown that for different response
functions of a medium nonlocality suppresses, as a rule, both the growth rate
peak and bandwidth of instability caused by random parameters. At the same
time, for a special form of the response functions there can be an
''anomalous'' subjection of nonlocality to the instability development which
leads to further increase of the growth rate. Along with the second-order
moments of the modulational amplitude, higher-order moments are taken into
account.Comment: This is a contribution to the Proc. of the Seventh Inter. Conference
''Symmetry in Nonlinear Mathematical Physics'' (June 24-30, 2007, Kyiv,
Ukraine), published in SIGMA (Symmetry, Integrability and Geometry: Methods
and Applications) at http://www.emis.de/journals/SIGMA
Modulational instability and nonlocality management in coupled NLS system
The modulational instability of two interacting waves in a nonlocal Kerr-type
medium is considered analytically and numerically. For a generic choice of wave
amplitudes, we give a complete description of stable/unstable regimes for zero
group-velocity mismatch. It is shown that nonlocality suppresses considerably
the growth rate and bandwidth of instability. For nonzero group-velocity
mismatch we perform a geometrical analysis of a nonlocality management which
can provide stability of waves otherwise unstable in a local medium.Comment: 15 pages, 12 figures, to be published in Physica Script