A kind of manufacturing method of optical fiber preform based on sleeve method

Abstract

Disclosed is a method for manufacturing an optical fiber preform based on a sleeve method, the method comprising the following steps: preparing an optical fiber mother core rod comprising a core layer and an inner cladding layer by using a VAD process, then heating and stretching the optical fiber mother core rod such that the curve degree of the stretched optical fiber core rod is less than 1 mm / m, then preparing a depressed layer by means of an OVD process, and finally, inserting the combined core rod into a quartz sleeve to form an optical fiber preform. The diameter of the prepared optical fiber preform may be up to 221 mm, the fiber pulling length of a single preform may be up to 2995 km, the attenuation coefficient of an optical fiber at a wavelength of 1310 nm is less than or equal to 0.305 dB / km, the attenuation coefficient of the optical fiber at a wavelength of 1383 nm is less than or equal to 0.275 dB / km, and the attenuation coefficient of the optical fiber at a wavelength of 1550 nm is less than or equal to 0.165 dB / km.

Description

technical field

[0001] The invention relates to a method for manufacturing an optical fiber preform rod based on a casing method, and belongs to the field of optical fiber preform rod manufacturing. Background technique

[0002] At present, there are four main methods for producing optical fiber preforms: Modified Chemical Vapor Deposition (MCVD), Microwave Plasma Chemical Vapor Deposition (PCVD), External Vapor Deposition (OVD) and Axial Vapor Deposition. (VAD), but there are the following problems in the manufacture of optical fiber preforms with large outer diameters only by the above method: the in-tube deposition method (MCVD and PCVD) is limited by the size of the liner, and cannot directly manufacture optical fiber preforms with large outer diameters, while the outside of the tube The deposition method (VAD and OVD) directly manufactures a mandrel with a large outer diameter, and the cost is relatively high, which cannot reflect the advantages of using the casing meth...