Open AccessGap solitons in PT-symmetric optical lattices with higher-order diffraction
Author(s) -
Lijuan Ge,
Ming Rong Shen,
Chunlan Ma,
Taocheng Zang,
Dai Lu
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.029435
Subject(s) - diffraction , physics , coupling constant , lattice constant , condensed matter physics , lattice (music) , optical lattice , dipole , instability , propagation constant , perturbation (astronomy) , nonlinear optics , optics , quantum mechanics , nonlinear system , superfluidity , acoustics
The existence and stability of gap solitons are investigated in the semi-infinite gap of a parity-time (PT)-symmetric periodic potential (optical lattice) with a higher-order diffraction. The Bloch bands and band gaps of this PT-symmetric optical lattice depend crucially on the coupling constant of the fourth-order diffraction, whereas the phase transition point of this PT optical lattice remains unchangeable. The fourth-order diffraction plays a significant role in destabilizing the propagation of dipole solitons. Specifically, when the fourth-order diffraction coupling constant increases, the stable region of the dipole solitons shrinks as new regions of instability appear. However, fundamental solitons are found to be always linearly stable with arbitrary positive value of the coupling constant. We also investigate nonlinear evolution of the PT solitons under perturbation.