Lattice solitons inPT-symmetric mixed linear-nonlinear optical lattices

Abstract

We report the existence and stability of lattice solitons in parity-time ($\mathcal{PT}$)-symmetric mixed linear-nonlinear optical lattices in Kerr media. We focus on studying the characteristic effects on soliton propagation in the semi-infinite gap if we consider different amplitudes of real and imaginary parts of both the linear refractive index modulation profile and of periodic nonlinearity-modulation spatial distribution. It was found that the combination of $\mathcal{PT}$-symmetric linear and nonlinear lattices can stabilize lattice solitons and can provide unique soliton properties. It is revealed that the parameters of the linear lattice periodic potential play a significant role in controlling the extent of the stability domains and that the lattice solitons can stably propagate only in the low-power regime.