Method for manufacturing large-diameter optical fiber mandril through PCVD process

Abstract

The invention relates to a method for manufacturing a large-diameter low-water peak optical fiber mandril through a high-deposition rate PCVD process, which comprises the following steps that: after a pure quartz liner with the outer diameter of 36 to 65mm is corroded and cleaned, PCVD processing is carried out; the pure quartz liner is arranged in a microwave resonant cavity heat insulation furnace, a microwave resonant cavity has axial reciprocating movement relative to the pure quartz liner, the movement speed is 15 to 30m / min, and the high-frequency power is 5.5 to 20.5KW; the deposition rate in the liner is 2.5 to 5.0g / min, and the single-layered deposition thickness is 1.0 to 3.0mu m; and after the deposition, an electric fusion shrink lathe shrinks to prepare the solid optical fiber mandril, the outer diameter of the mandril is 30 to 61mm, the diameter ratio of a cladding core layer b / a is more than or equal to 1.2 and less than 3.0, and the ratio of the outer diameter of the mandril to the diameter of the core layer c / a is more than or equal to 3.8 and less than 6.0. The method for manufacturing the large-diameter optical fiber mandril through the PCVD process not only has convenient manufacturing process and high deposition rate, but also can meet the design requirement on the diameter ratio of the cladding core layer in a wider scope and the optical fiber performance requirements on low water peak and low attenuation.

Description

technical field [0001] The invention relates to a method for manufacturing an optical fiber core rod, in particular to a method for manufacturing a large-diameter optical fiber core rod by a PCVD process with relatively high deposition rate and deposition efficiency, and belongs to the field of optical fiber communication. Background technique [0002] The manufacture of optical fiber preform is the first step in optical fiber manufacturing. As an optical waveguide, the optical fiber can be divided into core, optical cladding, mechanical cladding and coating layer in terms of the entire structure division. three parts. In the field of mass production of preforms, this multi-layer structure of preforms is often manufactured in a step-by-step process, that is, the core rod and the mechanical cladding sleeve are manufactured independently first, and the core rod and mechanical cladding are combined to form The preform as a whole. The core rod includes all of the core layer a...

AI Technical Summary

Problems solved by technology

However, with the continuous development of large-scale prefabricated rods, due to the limitation of the liner CSA designed by the scheme, the diameter of the mandrel made by it has reached the limit, and it can no longer adapt to the larger size of the sleeve-to-mandrel larger than 180 mm. The outer diameter is greater than 40 mm; the limited diameter will also limit the design of the cladding-core diameter ratio, which will increase the attenuation and water peak of the preform in the outsourcing process, especially after OVD outsourcing

Images