Eur. Phys. J. D (2014) 68: 322
https://doi.org/10.1140/epjd/e2014-40513-1

Regular Article

Two-dimensional defect solitons in parity-time-symmetric periodic optical lattices

¹ Engineering Research Center for Optoelectronics of Guangdong Province, School of Science, South China University of Technology, Guangzhou 510640, P.R. China
² School of Electronics and Information, Guangdong Polytechnic Normal University, Guangzhou 510665, P.R. China

^a e-mail: phhwang@scut.edu.cn

Received: 19 August 2013
Received in final form: 22 January 2014
Published online: 28 October 2014

Abstract

We report on the existence and stability of two-dimensional (2D) fundamental defect solitons (DSs) in parity-time (PT) symmetric periodic optical lattices based on focusing and defocusing nonlinear media, respectively. The stable regions of DSs in focusing and defocusing nonlinear media are calculated for the point defect. With the introduction of gain and loss component, some unique properties of 2D spatial DSs are displayed in such lattice potential. There exists transverse power-flow in the PT symmetric periodic optical lattice, and the DSs in the high power regions are unstable. Some properties in focusing nonlinear media are very different from those in defocusing nonlinear media. DSs in PT symmetric lattices with line defect based on focusing nonlinearity are studied as well.