Bragg solitons in nonlinear PT-symmetric periodic potentials

TL;DR

This paper demonstrates the existence of slow Bragg solitons in nonlinear PT-symmetric periodic structures, showing how PT symmetry influences wave coupling and soliton properties through analytical and numerical methods.

Contribution

It introduces a new class of slow Bragg solitons in nonlinear PT-symmetric structures and derives their solutions from a modified Thirring model.

Findings

PT-symmetric index modifies band structure

Closed-form solitary wave solutions obtained

Soliton properties depend on gain/loss profile

Abstract

It is shown that slow Bragg soliton solutions are possible in nonlinear complex parity-time (PT) symmetric periodic structures. Analysis indicates that the PT-symmetric component of the periodic optical refractive index can modify the grating band structure and hence the effective coupling between the forward and backward waves. Starting from a classical modified massive Thirring model, solitary wave solutions are obtained in closed form. The basic properties of these slow solitary waves and their dependence on their respective PT-symmetric gain/loss profile are then explored via numerical simulations.