Abstract: A method of for manufacturing a coated optical fiber includes depositing a conductive coating on the optical fiber and measuring a value of conductance of that coating. Featured within the manufacturing method is a method for measuring the thickness of the conductive coating on an insulator, e.g., carbon on an optical fiber, including the following steps. An electromagnetic field is established by an input signal. The conductively coated insulator is moved through the energized electromagnetic field. The conductive coating on the insulator is oriented with respect to the electric field so that their interaction increases transmission loss from input to output. An output signal is extracted from the electromagnetic field. From changes in the output signal with respect to a predetermined standard, or reference, the conductance and the thickness of the conductive coating are determined.

Abstract: A process for manufacturing an optical fiber includes the steps of heating and drawing material from a hot optical fiber preform; exposing the hot optical fiber to a compound containing carbon for depositing a carbon coating on the moving optical fiber; measuring an electrical property of the carbon coating; and in response to the measured electrical property, changing a parameter of the process for controlling a characteristic of the carbon coating on the moving optical fiber. Featured within the manufacturing method is a method for measuring the thickness of the carbon coating on the moving optical fiber. From the measured thickness of the carbon coating, a control signal is generated for changing one or more of the process parameters for depositing the carbon coating on the optical fiber from a precursor gas. The coated optical fiber continuously moves through the process without any physical contact. No interruption of the production process occurs.