Related Experiment Video
Updated: May 7, 2026

Automation of Mode Locking in a Nonlinear Polarization Rotation Fiber Laser through Output Polarization Measurements
Published on: February 28, 2016
Effects of parity-time symmetry in nonlinear Klein-Gordon models and their stationary kinks
A Demirkaya1, D J Frantzeskakis, P G Kevrekidis
1Mathematics Department, University of Hartford, 200 Bloomeld Avenue, West Hartford, Connecticut 06112, USA.
Abstract:
In this work, we introduce some basic principles of PT-symmetric Klein-Gordon nonlinear field theories. By formulating a particular antisymmetric gain and loss profile, we illustrate that the stationary states of the model do not change. However, the stability critically depends on the gain and loss profile. For a symmetrically placed solitary wave (in either the continuum model or a discrete analog of the nonlinear Klein-Gordon type), there is no effect on the steady state spectrum. However, for asymmetrically placed solutions, there exists a measurable effect of which a perturbative mathematical characterization is offered. It is generally found that asymmetry towards the lossy side leads towards stability, while towards the gain side produces instability. Furthermore, a host of finite size effects, which disappear in the infinite domain limit, are illustrated in connection to the continuous spectrum of the problem.
Related Concept Videos
Symmetry in Maxwell's Equations
Linear Approximation in Time Domain
For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the...
The Pauli Exclusion Principle
Properties of Fourier series II
A function f(t) is...
Linear Approximation in Frequency Domain
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear.
Oscillations about an Equilibrium Position

