Abstract: An apparatus for forming an optical element on the surface of a substrate by ejecting a curable light guide forming liquid from a nozzle onto the substrate and curing the curable light guide forming liquid. A waveguide may be formed by moving the nozzle in a linear pattern over the surface of the substrate during ejection of the liquid from the nozzle. Curing the liquid may include exposing the liquid to ultraviolet radiation, and the radiation may be applied to only a small portion of the liquid. A multilayered waveguide may be formed by ejecting a further light guide forming liquid onto the first and curing it. A core and cladding may be formed simultaneously by ejecting core forming liquid from an inner tube and cladding forming liquid from an annulus about the inner tube. The waveguide may be formed in a groove, and a splitter may be formed by branching a second waveguide from a first, or by laying out two parallel waveguides and connecting them.