Interface solitons excited between a simple lattice and a superlattice.

We demonstrate nonlinear surface states at the interface between optically-induced simple (periodic) and super (bi-periodic) photonic lattices. Depending on the excitation condition at the interface, we identify numerically and observe experimentally different types of interface solitons with characteristic phase structures under a self-focusing nonlinearity, including dipole-like "mixed-band" interface gap solitons.