Microfabrication technique for structuring non-planar electromagnetic waveguides

A method for manufacturing a multifunctional electromagnetic waveguide from a tapered optical fiber, the method comprising:

• mounting the optical fiber on a handling apparatus which may be actuated to translationally move the optical fiber along at least one translation axis and rotate the optical fiber about a longitudinal axis thereof,
• submerging a tapered section of the optical fiber in a photoresist and subjecting the photoresist to two-photon polymerization to form a first mask defining a shape of at least one optical window,
• subjecting the masked tapered section to a plurality of directional flows of metal material to form a first metal layer around the tapered section, leaving at least one lateral edge of the first mask uncovered,
• removing the first mask by chemical etching in such a way to uncover said at least one optical window,
• depositing a transparent, conformal first layer around the tapered section, said transparent, conformal first layer being made of insulating material,
• depositing a second metal layer around the insulating transparent, conformal first layer,
• submerging the tapered section in the photoresist and subjecting the photoresist to two-photon polymerization to form, at the tapered section, a second mask defining a shape of at least one conductive track,
• removing, by chemical etching, the second metal layer where the second metal layer is not covered by the second mask, and
• removing the second mask by chemical etching in such a way to uncover said at least one conductive track.