Tamm oscillations in semi-infinite nonlinear waveguide arrays

We demonstrate numerically the existence of nonlinear Tamm oscillations at the interface between a substrate and one-dimensional waveguide array with both cubic and saturable, self-focusing and self-defocusing nonlinearity. Light is trapped in the vicinity of the boundary of the array due to the interplay between the repulsive edge potential and Bragg reflection inside the array. In the special case when this potential is linear these oscillations reduce themselves to surface Bloch oscillations.