A Lagrangian approach to modulational instability in nonlocal nonlinear Kerr media

Using a time-dependent variational approach to study modulational instability (MI) of plane waves in Kerr media with nonlocal nonlinearity in its linear stage, I obtain and analyze the set of ordinary differential equations that describe the evolution over time of the amplitude and phase of modulational perturbations. From those equations, I obtain the effective potential of the system and perform numerical simulations to verify the theoretical results. For the nonlinear stage, I find that the degree of nonlocality notably changes the behavior of MI in the central oscillatory region of the integration. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

By using a time-dependent variational approach, this study investigates the modulational instability of plane waves in Kerr media with nonlocal nonlinearity. Ordinary differential equations describing the evolution of modulational perturbations are obtained and analyzed, along with numerical simulations to confirm theoretical results. The level of nonlocality significantly impacts the behavior of modulational instability in the nonlinear stage.