Abstract: A process for manufacturing an optical fiber, includes the steps of: a) producing a soot core preform by depositing a core material on a substrate; b) removing the substrate from the soot preform leaving an axial cavity along the longitudinal axis of the soot core preform; (c) drying and consolidating the soot core preform so as to obtain a glass core preform having an axial hole corresponding to the axial cavity; d) reducing a diameter of the axial hole; and e) stretching the glass core preform so as to substantially close the axial hole, wherein the process further includes the step of measuring at least one geometric characteristic of the axial hole of the glass core preform.

Abstract: A process for manufacturing an optical fiber, includes the steps of: a) producing a soot core preform by depositing a core material on a substrate; b) removing the substrate from the soot preform leaving an axial cavity along the longitudinal axis of the soot core preform; (c) drying and consolidating the soot core preform so as to obtain a glass core preform having an axial hole corresponding to the axial cavity; d) reducing a diameter of the axial hole; and e) stretching the glass core preform so as to substantially close the axial hole, wherein the process further includes the step of measuring at least one geometric characteristic of the axial hole of the glass core preform.