Hermetic Carbon Coatings for Electro-Thermal All-Fiber Phase Modulators

Abstract

Joule effect and thermal response of several carbon-coated fibers are modelled and analysed. An electro-thermally driven all-fiber phase modulator based on these principles is proposed and a proof of concept of it is characterized. This kind of fibers could be the basis for developing all-fiber components aimed to operate in environments where the strength increase and impermeability to hydrogen diffusion guaranteed by the carbon coating is crucial.

Graphene-Material Based Nanocomposite-Coated Optical Fibres: A Multi-Functional Optical Fibre for Improved Distributed Sensing Performance in Harsh Environment

“…This thin 20 nm carbon film is usually added between the fibre cladding and the external coating to protect the optical fibre against the diffusion of small molecules into the glass to protect its mechanical integrity when used in harsh environment and oil & gas applications [19][20]. Moreover, the carbon coating is an electrically conductive medium that can be used to modify the refractive index of long lengths of fibres in a controlled way by applying a current on it [21]. To do so, the external acrylate or polyimide coating needs to be removed to contact the carbon coating, which compromises the strength of the fibre and, subsequently, the fibre component made from it.…”