Optical fiber

Patent metadata

Field	Value
Publication number	US-9829625-B2
Application number	US-201615143687-A
Country	US
Kind code	B2
Filing date	May 2, 2016
Priority date	May 8, 2015
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

An optical fiber comprises a glass fiber which comprises a core and a cladding, a primary resin coating layer which covers the periphery of the glass fiber, and a secondary resin coating layer which covers the periphery of the primary resin coating layer. The glass fiber is a multimode fiber having a core diameter of 40-60 μm and a cladding diameter of 90-110 μm, and the primary resin coating layer is a layer formed by curing a curable resin composition which comprises oligomers, monomers, and a reaction initiator, the curable resin composition containing a one-end-capped oligomer in an amount of 30% by mass or larger based on all the oligomers.

First claim

The invention claimed is:

1. An optical fiber comprising a glass fiber which comprises a core and a cladding, a primary resin coating layer which covers a periphery of the glass fiber, and a secondary resin coating layer which covers a periphery of the primary resin coating layer, wherein
the glass fiber is a multimode fiber having a core diameter of 40-60 μm and a cladding diameter of 90-110 μm, and
the primary resin coating layer is a layer formed by curing a curable resin composition which comprises oligomers, monomers, and a reaction initiator, the curable resin composition containing a one-end-capped oligomer which has a nonreactive terminus and a reactive group on the other end in an amount of 30% by mass or larger based on all the oligomers.

2. The optical fiber according to claim 1 , wherein the primary resin coating layer has a Young's modulus of 0.5 MPa or less.

3. The optical fiber according to claim 1 , which has a non-strippable resin coating layer disposed between the cladding and the primary resin coating layer, the non-strippable resin layer having an outer diameter of 122-128 μm.

4. The optical fiber according to claim 1 , wherein the glass fiber has, on a periphery of the core, a trench which is a portion having a lower refractive index than the cladding, and wherein the core has a refractive index difference of 0.7% or larger, the trench has a refractive index difference of −0.2% or less, and the trench has a radial-direction width of 1 μm or larger.

5. The optical fiber according to claim 4 , wherein the trench has a refractive index difference of −0.4% or less.

6. The optical fiber according to claim 1 , wherein when a transmission loss of the optical fiber wound on a mandrel with a diameter of 15 mm so as to make two turns is measured using signal light having a wavelength of 850 nm and is compared with a transmission loss, measured using signal light having a wavelength of 850 nm, of the optical fiber wound into a loose and coreless bundle with a diameter of 30 cm, then the former transmission loss is not higher by more than 0.2 dB than the latter transmission loss.

7. The optical fiber according to claim 1 , wherein when a transmission loss of the optical fiber wound on a mandrel with a diameter of 4 mm so as to make 0.5 turns is measured using signal light having a wavelength of 850 nm and is compared with a transmission loss, measured using signal light having a wavelength of 850 nm, of the optical fiber wound into a loose and coreless bundle with a diameter of 30 cm, then the former transmission loss is not higher by more than 2.5 dB than the latter transmission loss.

Assignees

• Sumitomo Electric Industries

Inventors

• Homma Yuya

Classifications

• C03C25/1065

  Multiple coatings · CPC title

• G02B1/14

  Protective coatings, e.g. hard coatings · CPC title

• G02B6/02395

  Glass optical fibre with a protective coating, e.g. two layer polymer coating deposited directly on a silica cladding surface during fibre manufacture (G02B6/02052, G02B6/02057, G02B6/024, G02B6/032, G02B6/105, G02B6/14 take precedence; coating on fibre gratings G02B6/02104; multilayer core or cladding G02B6/036; reinforcing splice joints G02B6/2558; optical cables, i.e. comprising protective structures external to the protective coating such as a jacket or plural coated optical fibres G02B6/44; coating of glass to obtain optical fibres C03C25/104) · CPC title

• G02B6/0288 Primary

  Multimode fibre, e.g. graded index core for compensating modal dispersion · CPC title