Discrete spatial solitons
/sup W/e will review our recent experimental results in nonlinear waveguide arrays and discuss the differences between continuous and discrete nonlinear systems. When a discrete soliton is launched in a waveguide array, it resembles in many ways its continuous counterpart. However, since a slab is invariant to translations and rotations, no significant changes are observed when standard spatial solitons are launched at an angle, or in different initial positions. When a discrete soliton is launched with a phase-gradient across the initial distribution, it hops sideward while propagating along the array. The deviation from the continuous case appears particularly at higher powers, where the soliton may lock to the initial waveguides, suppressing the transverse motion. The previous situation can be reversed by launching a straight beam in an arbitrary position of the array. An asymmetric distribution of power in adjacent waveguides can generate a nonlinear phase gradient and therefore, induce power dependent steering of the discrete soliton. We will present experimental results showing how significant steering of a "discrete" spatial soliton beam can be obtained through a much smaller "control" of the input beam parameters.