Controlled generation and steering of spatial gap solitons

The first fully controlled generation of immobile and slow spatial gap solitons was studied in nonlinear periodic systems with band-gap spectra. The key features of gap solitons that distinguish them from discrete solitons, including a dynamical transformation of gap solitons due to nonlinear interband coupling, were also observed. It was shown that generated gap solitons move to the left when the grating is tilted to the right. It was suggested that the group-velocity dispersion (GVD) of gap solitons can be increased or decreased by changing the lattice period and modulation depth.