Abstract: An optical fiber includes a coating comprising a cross-linked network comprising the reaction product of monomers and oligomers and at least one polymer dispersed or interpenetrated in the cross-linked network. The oligomer and polymer components used are at least partially fluorinated. The fiber-coating composition of the invention presents a refractive index that is low while satisfying the conditions for industrial fiber-drawing.

Abstract: The present invention relates to an optical fiber (1?) having at least one Bragg grating (11), the fiber comprising a core (2) surrounded successively by cladding (3) and a coating (4), said fiber being obtained by writing said grating in the core and/or the cladding directly through the coating which is made of a material containing an organic substance that is substantially transparent to the ultraviolet type radiation used for writing said grating, wherein the material of said coating contains an inorganic substance that is not miscible with the organic substance and that is distributed in substantially uniform manner in said material.

Abstract: The present invention relates to an optical fiber (1) having at least one Bragg grating (11), the fiber comprising a core (2) surrounded successively by cladding (3) and by a coating (4), said grating being obtained by being written directly in the core and/or the cladding of the fiber through the coating which is made of a material that is substantially transparent to ultraviolet type radiation used for writing said grating, wherein the material of said coating contains a first polymer network interpenetrated by a second polymer.