METHOD AND DEVICE FOR PRODUCING CONDUCTIVE THIN FILM-COATED OPTICAL FIBER

摘要

This invention provides a method and a device for producing an optical fiber which make it possible to measure the film characteristics of the inorganic thin films continuously and electromagnetically in non-contact therewith. Firstly, an optical fiber drawn from a preform is coated with a conductive thin film. Secondly, the optical fiber is passed through a high-frequency magnetic field to measure an eddy current generated in the conductive thin film in non-contact therewith so as to measure the film characteristics of the conductive thin film. The device for producing an optical fiber used for this invention comprises a fiber drawing furnace to draw an optical fiber, thin film coating device, and film characteristics measuring device. The film characteristics measuring means measure the film characteristics of the conductive thin film, based on a variation of an alternating current impedance of the detection coil generated when the optical fiber is passed through the hollow interior of the detection coil.