Abstract: A method and apparatus for manufacturing a graded-index plastics optical fiber of continuously varying index profile, starting from a particular polymer P and a particular compound M1, the method including the steps of: preparing two compositions of different refractive index, allowing the compositions to diffuse one into the other, and spinning the compositions so as to obtain the fiber, wherein, prior to extrusion, the two compositions are subjected to active mixing, and extrusion of the fiber is followed by curing.

Abstract: A method of continuous application of a graded index plastics optical fiber in which the refractive index is highest in the center and decreases progressively towards the periphery, said fiber having a plurality of layers of resin deposited concentrically, the method comprising making a plurality of mixtures, each mixture comprising at least one polymer P and a reactive diluting agent including at least two monomers, then depositing said mixtures in the form of coaxial layers, allowing interdiffusing to take place between the layers, and finally crosslinking the polymer P and/or the reactive diluting agent.