Method of processing optical fiber and method of estimating therefor

Patent metadata

Field	Value
Publication number	US-2016002105-A1
Application number	US-201514791624-A
Country	US
Kind code	A1
Filing date	Jul 6, 2015
Priority date	Jul 7, 2014
Publication date	Jan 7, 2016
Grant date	—

Abstract

A method of processing an optical fiber of the invention includes: a determination step of determining at least an ambient temperature of conditions of a diffusion treatment that causing an optical fiber to be subjected to an non-oxygen bridging atmosphere; an exposure step of exposing the optical fiber to a gas including an oxygen bridging element that is capable of processing the Non-Bridging Oxygen Hole Centers by being bonded to a non-bridging oxygen in the optical fiber, and causing the oxygen bridging element to infiltrate into the optical fiber; and a diffusion step of subsequently causing the optical fiber to be subjected to the non-oxygen bridging atmosphere in the exposure ambient temperature which is determined by the determination step and at which the optical fiber is subjected to the non-oxygen bridging atmosphere, and thereby diffusing the oxygen bridging element into the optical fiber.

First claim

What is claimed is:

1 . A method of processing an optical fiber, comprising:
a preparation step of preparing an optical fiber that comprises a core and a cladding surrounding the core and that is made of a silica-based glass; a determination step of determining at least an ambient temperature of conditions of a diffusion treatment that causing the optical fiber to be subjected to an non-oxygen bridging atmosphere not including an oxygen bridging element, the determination step comprising:
a first step of estimating an amount of Non-Bridging Oxygen Hole Centers in the entire optical fiber and estimating an amount of the oxygen bridging element required for processing the Non-Bridging Oxygen Hole Centers in the entire optical fiber;
a second step of determining correlation that is based on a diffusion model of gaseous molecules of an oxygen bridging element, is related to the oxygen bridging element supplied to the optical fiber, and is between an exposure ambient temperature at which the optical fiber is subjected to the non-oxygen bridging atmosphere, an exposure time at which the optical fiber is subjected to the non-oxygen bridging atmosphere in an exposure period in which the optical fiber is subjected to the non-oxygen bridging atmosphere, and the amount of the oxygen bridging element in the optical fiber; and
a third step of determining, based on the correlation determined by the second step, the exposure ambient temperature at which the optical fiber is subjected to the non-oxygen bridging atmosphere;
an exposure step of exposing the optical fiber to a gas including an oxygen bridging element that is capable of processing the Non-Bridging Oxygen Hole Centers by being bonded to a non-bridging oxygen in the optical fiber, and causing the oxygen bridging element to infiltrate into the optical fiber; and a diffusion step of subsequently causing the optical fiber to be subjected to the non-oxygen bridging atmosphere in the exposure ambient temperature which is determined by the third step of the determination step and at which the optical fiber is subjected to the non-oxygen bridging atmosphere, and thereby diffusing the oxygen bridging element into the optical fiber.

2 . The method according to claim 1 , wherein
a gas including deuterium is used as the gas including the oxygen bridging element.

3 . The method according to claim 1 , wherein
the non-oxygen bridging atmosphere is an air atmosphere.

4 . The method according to claim 1 , wherein
in the third step of the determination step, based on the correlation determined by the second step, an exposure temperature and a corresponding exposure time corresponding to the exposure temperature are determined, the exposure temperature being capable of causing the amount of the required oxygen bridging element to exist in the optical fiber after the optical fiber is subjected to the non-oxygen bridging atmosphere for a shortest period of time, the exposure temperature and the corresponding exposure time are, respectively, determined as a temperature and a time, at which the optical fiber is subjected to the non-oxygen bridging atmosphere in the diffusion step, the diffusion step is carried out under the condition of the determined temperature and the determined time.

5 . The method according to claim 1 , wherein
the first step of the determination step comprises: a first process of estimating an amount of Non-Bridging Oxygen Hole Centers in the core based on transmission loss measurement data obtained by measuring a transmission loss of the optical fiber before the exposure step; a second process of estimating the amount of Non-Bridging Oxygen Hole Centers in the entire optical fiber, based on correlation between an amount of Non-Bridging Oxygen Hole Centers in the entire optical fiber which is determined from cumulative result data associated with optical fibers and the amount of Non-Bridging Oxygen Hole Centers in the core, and based on the estimated amount of Non-Bridging Oxygen Hole Centers in the core; and a third process of estimating the amount of the oxygen bridging element required for processing the Non-Bridging Oxygen Hole Centers in the entire optical fiber based on the estimated amount of Non-Bridging Oxygen Hole Centers in the entire optical fiber.

6 . The method according to claim 5 , wherein
in the first process of the first step of the determination step, wavelength region data of the transmission loss measurement data obtained by measuring a transmission loss of the optical fiber before the exposure step, which avoids an absorption peak due to the Non-Bridging Oxygen Hole Centers, is externally fitted on a wavelength region in which the absorption peak exists, a transmission loss at the absorption peak due to the Non-Bridging Oxygen Hole Centers is thereby determined, and the amount of Non-Bridging Oxygen Hole Centers in the core is estimated based on the transmission loss.

7 . The method according to claim 6 , wherein
in the first process of the first step of the determination step, measurement data associated with a short-wavelength with respect to a transmission loss in which the wavelength λ of the optical fiber is less than or equal to 1000 nm is converted into λ −4 , loss data of a wavelength region including a region other than a wavelength region in which λ −4 is 4 to 8 and including at least a region in which λ −4 is 2 to 3 is subjected to linear approximation, a difference between a transmission loss value of 630 nm on an extension line of the approximation straight line and a practically-measured transmission loss value of 630 nm is defined as a transmission loss due to the Non-Bridging Oxygen Hole Centers, and the amount of Non-Bridging Oxygen Hole Centers in the core is estimated based on the transmission loss.

8 . A method of estimating an amount of oxygen bridging element required for processing Non-Bridging Oxygen Hole Centers in an entire optical fiber that comprises a core and a cladding surrounding the core and that is made of a silica-based glass in the case of exposing the optical fiber to a gas including an oxygen bridging element that is capable of processing the Non-Bridging Oxygen Hole Centers by being bonded to a non-bridging oxygen in the optical fiber, and causing the oxygen bridging element to infiltrate into the optical fiber, the method comprising:
a first process of obtaining transmission loss data by measuring a transmission loss of the optical fiber before exposing the optical fiber to the gas including the oxygen bridging element, and estimating the amount of Non-Bridging Oxygen Hole Centers in the core based on the transmission loss data; a second process of estimating the amount of Non-Bridging Oxygen Hole Centers in the entire optical fiber, based on correlation between an amount of Non-Bridging Oxygen Hole Centers in the entire optical fiber which is determined from cumulative result data associated with optical fibers in previous cases and the amount of Non-Bridging Oxygen Hole Centers in the core, and based on the estimated amount of Non-Bridging Oxygen Hole Centers in the core; and a third process of estimating the amount of the oxygen bridging element required for processing the Non-Bridging Oxygen Hole Centers in the entire optical fiber based on the estimated amount of Non-Bridging Oxygen Hole Centers in the entire optical fiber.

9 . The method according to claim 8 , wherein
the gas including the oxygen bridging element is a gas including deuterium.

10 . The method according to claim 8 , wherein
the non-oxygen bridging atmosphere is an air atmosphere.

11 . The method according to claim 8 , wherein
in the first process, wavelength r

Assignees

• Fujikura Ltd

Inventors

• Hamaguchi Hiroki

Classifications

• C03B2201/22

  doped with deuterium · CPC title

• C03C2201/22

  containing deuterium · CPC title

• C03C13/047 Primary

  containing deuterium · CPC title

• C03C25/106

  Single coatings · CPC title

• C03B37/01

  Manufacture of glass fibres or filaments · CPC title