METHOD OF FORMING A GRATING IN A WAVEGUIDE

A refractive-index grating fabricated in an optical fiber (20) having a multilayer (23, 24) coating and a method for making refractive-index patterns such as gratings in optical fibers such that the mechanical properties of the original fiber are preserved. The patterns are written into the optical fiber by partially stripping away the outer coating (24) of the fiber, exposing the core (23) of the fiber through the remainder of the coating with an actinic radiation (26) to form the pattern in the photosensitive core (21) of the fiber, followed by recoating the fiber in the stripped area (28) to provide protection of the newly formed pattern from corruption and to preserve the mechanical properties of the fiber. A refractive-index grating fabricated in an optical fiber having a multilayer coating and a method for making refractive-index patterns such as gratings in optical fibers such that the mechanical properties of the original fiber are preserved. The patterns are written into the optical fiber by partially stripping away the outer coating of the fiber, exposing the core of the fiber through the remainder of the coating with an actinic radiation to form the pattern in the photosensitive core of the fiber, followed by recoating the fiber in the stripped area to provide protection of the newly formed pattern from corruption and to preserve the mechanical properties of the fiber. L'invention porte sur un réseau d'indices de réfraction tracé dans une fibre optique à plusieurs gaines et sur un procédé d'exécution de motifs d'indices de réfraction tels que des réseaux, tout en conservant les propriétés mécaniques originales de la fibre. Le traçage des motifs dans la fibre se fait comme suit: dénudage partiel de la fibre; exposition de la partie dénudée à travers le reste des gaines à un rayonnement actinique pour former le motif dans le noyau photosensible de la fibre; regainage de la partie dénudée de la fibre pour protéger le motif nouvellement formé des altérations et maintenir les propriétés mécaniques de la fibre.