Stability analysis for continuous waves in nonlocal random nonlinear media
Stability (instability) of continuous waves in nonlocal random non-Kerr nonlinear media is studied analytically and numerically. Two featured sorts of nonlinearity are explored - a cubic-quintic model and a model with saturable nonlinearity. Fluctuating medium parameters are modelled by the Gaussian white noise. It is shown for different response functions of a medium that 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 as well.