Soliton emission in amplifying lattice surfaces.

We address surface solitons supported by the interface of optical lattices imprinted in saturable media with surface-localized gain. The nonlinearity saturation puts restrictions on the maximal energy flow carried by surface solitons. As a consequence, the presence of a thin amplifying layer near the surface results in the controllable emission of solitons toward the lattice at angles depending on the amplification rate and lattice depth.