Gradient index lenses are described that are integrated within a planar
optical structure. The gradient index lens is optically coupled to a
planar optical waveguide. In some embodiments, the gradient index lens
with variation in index-of-refraction n one dimension is within an
optical fiber. The optical fiber includes cladding at least along the
edges of the central plane of the gradient index lens. Methods for
forming the integrated structures are described. Further optical
structures involving the gradient index lenses are also described.