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 in 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.