Figure 3. Formation of double-discrete solitons in locally PT-symmetric lattices (measurement).

(a) The band structure of the infinite lattice with G=1.1 is complex over the Brillouin zone. The real and imaginary parts are shown in black and red, respectively. (b,c) The eigenvalue–energy and width parametric curves of the discrete solitons in this lattice. As the power gradually increases (d–f) a discrete soliton forms at P≈120 mW.