US 7,062,941 B2Granted

Manufacturing method of optical fiber preform

AssigneeSumitomo Electric Industries, Ltd.

InventorsMasashi Onishi, Eiji Yanada, Masaaki Hirano, Hideyuki Ijiri

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Abstract

A method for manufacturing an optical fiber preform that can produce an optical fiber having desired characteristics over the longer length thereof. A crude preform provided with a core region and a cladding region is prepared (Step S1), and at a plurality of positions in the longitudinal direction of the crude preform, a refractive index profile in the cross-section of the crude preform is measured (Step S2). Then, the shape of the cladding region is demarcated based on the shape of the profile (Step S3). Subsequently, the crude preform is ground based on the results of the demarcation (Step S4). Thus, an optical fiber preform that enables the manufacture of an optical fiber having target characteristics is manufactured.

Claims5

Dependent claims

A method of manufacturing an optical fiber preform, the method comprising sequentially:

preparing a crude preform for manufacturing an optical fiber preform;
measuring the refractive indexes along a straight line in the cross-section which is perpendicular to the axis of the crude preform at a plurality of positions in the longitudinal direction of the crude preform;
estimating characteristics of an optical fiber to be produced from the preform based on the measured refractive indexes;
comparing the estimated characteristics to target characteristics of the optical fiber;
demarcating the outer diameters of the crude preform at intermediate positions between the measured portions to eliminate any differences between the target characteristics and the estimated characteristics;
and
selectively grinding the crude preform based on the results of demarcating the outer diameters.

4 more elements

Dependencies are inferred from the claim text.