Method for manufacturing an optical fiber preform by mcvd
OwnerChoon-Keun Hong, Byung-Yoon Kang +2inventors
InventorsChoon-Keun Hong, Byung-Yoon Kang, Dong-Wook Lee, Byung-Chul Kang
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Abstract
Disclosed is a method for manufacturing an optical fiber preform in MCVD, which simultaneously performs an etching process for injecting a reaction gas for etching into a tube and a collapsing process for heating and collapsing the tube in order to minimize or eliminate an index dip existing at the center of the preform core. By using this method, the index dip phenomenon of the optical fiber preform can be minimized or eliminated, so it is possible to make an optical fiber having improved optical characteristics, particularly having improvement in a bandwidth and a polarization mode dispersion (PMD).
Claims14
A method for manufacturing an optical fiber preform by MCVD comprising:
- a depositing process for forming a clad/core deposition layer on an inner wall of a quartz tube;
- a collapsing process for collapsing the quartz tube on which the deposition layer is formed by heating the quartz tube at a higher temperature than a softening temperature;
- an etching/collapsing process for etching and collapsing the quartz tube at the same time by injecting an reaction gas for etching into the quartz tube together with heating the tube at a higher temperature than a softening temperature so that the inner diameter of the tube is optimized just before a following closing process;
- and
- a closing process for forming an optical fiber preform without a hollow portion by heating the quartz tube having the optimized inner diameter at a higher temperature than a softening temperature,
- whereby an index dip existing at a center of the optical fiber preform core is minimized.
Dependencies are inferred from the claim text.