Mixed-gap vector solitons in parity-time-symmetric mixed linear–nonlinear optical lattices

We report on the existence and stability of mixed-gap vector solitons in parity-time (PT)-symmetric mixed linear-nonlinear optical lattices. The first component is single-peaked, and the propagation constant is in the semi-infinite gap. The second component is the out-of-phase dipole mode; its propagation constant belongs to the first finite gap. The imaginary part and the depth of the PT-symmetric nonlinear optical lattice will significantly affect the existence and stability domains of these vector solitons. The propagation constant of the first component can also influence the existence and stability of the vector solitons. Finally, we also study the effect of the PT-symmetric linear optical lattice on the vector solitons' stability. (C) 2014 Optical Society of America