Asymmetric modulation instability in nonlinear metamaterial waveguides
Document Type
Article
Publication Date
7-1-2023
Abstract
In this paper, we explore the formation of asymmetric modulation instability spectrum in the metamaterials as a result of the joined effect of self-steepening and intra-pulse Raman scattering. In general, the modulation instability gain spectrum is symmetric about the zero perturbation frequency. Here we observe asymmetric modulation instability gain spectrum and the asymmetry depends on the sign of the refractive index of the medium. When the refractive index of the medium is negative the band with high modulation instability gain is observed at positive detuning frequency regime in contrast to the case of positive refractive index regime where the band with high modulation instability gain is present at a negative detuning frequency regime. This preponderance is attributed to the opposite directionality of phase velocity and energy flow in a negative index material. Our study provides additional ways to tune soliton and ultrashort pulses utilizing engineering freedom of metamaterials.
Keywords
Nonlinear metamaterials, Modulation instability, Intra-pulse Raman scattering
Divisions
MathematicalSciences
Funders
None
Publication Title
PHYSICA SCRIPTA
Volume
98
Issue
7
Publisher
IOP Publishing Ltd
Publisher Location
TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND