Modulational instability in asymmetric coupled wave functions

I. Kourakis, P. K. Shukla

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


The evolution of the amplitude of two nonlinearly interacting waves is considered, via a set of coupled nonlinear Schrödinger-type equations. The dynamical profile is determined by the wave dispersion laws (i.e. the group velocities and the group velocity dispersion terms) and the nonlinearity and coupling coefficients, on which no assumption is made. A generalized dispersion relation is obtained, relating the frequency and wave-number of a small perturbation around a coupled monochromatic (Stokes') wave solution. Explicitly stability criteria are obtained. The analysis reveals a number of possibilities. Two (individually) stable systems may be destabilized due to coupling. Unstable systems may, when coupled, present an enhanced instability growth rate, for an extended wave number range of values. Distinct unstable wavenumber windows may arise simultaneously.

Original languageBritish English
Pages (from-to)321-325
Number of pages5
JournalEuropean Physical Journal B
Issue number1-2
StatePublished - Mar 2006


Dive into the research topics of 'Modulational instability in asymmetric coupled wave functions'. Together they form a unique fingerprint.

Cite this