  We report Anderson localization in two-dimensional optical waveguide arrays
with disorder in waveguide separation introduced along one axis of the array,
in an uncorrelated fashion for each waveguide row. We show that the anisotropic
nature of such disorder induces a strong localization along both array axes.
The degree of localization in the cross-axis remains weaker than that in the
direction in which disorder is introduced. This effect is illustrated both
theoretically and experimentally.
