English
Related papers

Related papers: Modulational instability in $\mathcal{PT}$-symmetr…

200 papers

The modulation instability (MI) is a universal mechanism that is responsible for the disintegration of weakly nonlinear narrow-banded wave fields and the emergence of localized extreme events in dispersive media. The instability dynamics is…

Fluid Dynamics · Physics 2017-09-06 O. Kimmoun , H. C. Hsu , B. Kibler , A. Chabchoub

We propose a multi-field-coupled atomic model that exhibits controllable $symmetric$ and $asymmetric$ evolution of significantly enhanced diffraction peaks in an opto-atomic grating at far-field regime. Such results are obtained by the…

We investigate theoretically the fundamental phenomenon of the spontaneous, noise-induced modulational instability (MI) of a plane wave. The long-term statistical properties of the noise-induced MI have been previously observed in…

Exactly Solvable and Integrable Systems · Physics 2019-12-11 Andrey Gelash , Dmitry Agafontsev , Vladimir Zakharov , Gennady El , Stephane Randoux , Pierre Suret

We explore the consequences of incorporating parity and time reversal ($\mathcal{PT}$) symmetries on the dynamics of nonreciprocal light propagation exhibited by a class of nonuniform periodic structures known as chirped…

Pattern Formation and Solitons · Physics 2019-11-13 S. Vignesh Raja , A. Govindarajan , A. Mahalingam , M. Lakshmanan

The unique spectral behavior exhibited by a class of non-uniform Bragg periodic structures, namely chirped and apodized fiber Bragg gratings (FBGs) influenced by parity and time reversal ($\mathcal{PT}$) symmetry, is presented. The…

Optics · Physics 2020-03-18 S. Vignesh Raja , A. Govindarajan , A. Mahalingam , M. Lakshmanan

The modulation instability (MI) is responsible for the disintegration of a regular nonlinear wave train and can lead to strong localizations in a from of rogue waves. This mechanism has been studied in a variety of nonlinear dispersive…

Pattern Formation and Solitons · Physics 2024-05-31 Yuchen He , Jinghua Wang , Bertrand Kibler , Amin Chabchoub

We show that, Four wave mixing (FWM) processes of grating can be controlled by the presence of interactions with a quantum dot or a molecule made by coupled quantum dots. By choosing the appropriate level spacing for the quantum emitter,…

Quantum Physics · Physics 2015-07-02 Shailendra Kumar Singh , Mehmet Emre Tasgin

We report the spectral features of a phase-shifted parity and time ($\mathcal{PT}$)-symmetric fiber Bragg grating (PPTFBG) and demonstrate its functionality as a demultiplexer in the unbroken $\mathcal{PT}$-symmetric regime. The length of…

Optics · Physics 2020-08-05 S. Vignesh Raja , A. Govindarajan , A. Mahalingam , M. Lakshmanan

We present a novel approach to the analysis of a full model of scalar modulation instability (MI) by means of a simple geometrical description in the power vs. frequency plane. This formulation allows to relate the shape of the MI gain to…

Optics · Physics 2017-01-20 S. M. Hernandez , P. I. Fierens , J. Bonetti , A. D. Sánchez , D. F. Grosz

In this paper, we study modulation instabilities (MI) in a one-dimensional chain configuration of a flexible mechanical metamaterial (flexMM). Using the lumped element approach, flexMMs can be modeled by a coupled system of discrete…

Applied Physics · Physics 2023-05-31 Antoine Demiquel , Vassos Achilleos , Georgios Theocharis , Vincent Tournat

In this work, we observe that the $\mathcal{PT}$-symmetric fiber Bragg gratings (PTFBGs) with saturable nonlinearity (SNL) exhibit ramp-like, mixed, optical multistability (OM) in the broken regime. The interplay between nonlinearity and…

Optics · Physics 2024-04-23 S. Vignesh Raja , A. Govindarajan , M. Lakshmanan

This paper explores structure formation in two-dimensional magnetohydrodynamic (MHD) turbulence as a modulational instability (MI) of turbulent fluctuations. We focus on the early stages of structure formation and consider simple…

Plasma Physics · Physics 2024-02-21 S. Jin , I. Y. Dodin

Modulational instability (MI) of ion-acoustic waves (IAWs) has been theoretically investigated in a plasma system which is composed of inertial warm adiabatic ions, isothermal positrons, and two temperature superthermal electrons. A…

Plasma Physics · Physics 2017-06-20 N. A. Chowdhury , M. M. Hasan , A. Mannan , A. A. Mamun

We present detailed experimental study on noise-seeded intermodal modulation instability (IM-MI) in normal dispersion region of a conventional step-index fiber. The sharp refractive index contrast between core and cladding leads to large…

Optics · Physics 2020-01-08 Partha Mondal , Shailendra K. Varshney

A generalized plasma model having warm ions, iso-thermal electrons, super-thermal electrons and positrons is considered to theoretically investigate the modulational instability (MI) of ion-acoustic waves (IAWs). A standard nonlinear…

Plasma Physics · Physics 2020-06-04 S. Banik , N. M. Heera , T. Yeashna , M. R. Hassan , R. K. Shikha , N. A. Chowdhury , A. Mannan , A. A. Mamun

The occurrence of the modulational instability (MI) in transverse dust lattice waves propagating in a one-dimensional dusty plasma crystal is investigated. The amplitude modulation mechanism, which is related to the intrinsic nonlinearity…

Soft Condensed Matter · Physics 2009-11-10 I. Kourakis , P. K. Shukla

We present a comprehensive study of modulational instability (MI) in a binary Bose-Einstein condensate with spin-orbit coupling, confined to a deep optical lattice. The system is modeled by a set of discrete Gross-Pitaevskii equations.…

Quantum Gases · Physics 2025-09-19 R. Sasireka , S. Sabari , A. Uthayakumar , Lauro Tomio

In the context of $\mathcal{PT}$-symmetric fiber Bragg gratings, tailoring the nonlinear profile along the propagation coordinate serves to be a new direction for realizing low-power all-optical switches. The scheme is fruitful only when…

Optics · Physics 2022-07-06 S. Sudhakar , S. Vignesh Raja , A. Govindarajan , K. Batri , M. Lakshmanan

We study modulational stability and instability in the Whitham equation, combining the dispersion relation of water waves and a nonlinearity of the shallow water equations, and modified to permit the effects of surface tension and constant…

Analysis of PDEs · Mathematics 2015-08-28 Vera Mikyoung Hur , Mathew A. Johnson

We study modulational instability in a fiber system resembling a dispersion-managed link where the sign of the group-velocity dispersion varies randomly according to a telegraph process. We find that the instability gain of stochastic…

Optics · Physics 2023-11-13 Andrea Armaroli , Matteo Conforti