Optical fiber inspecting device, optical fiber manufacturing apparatus, method for inspecting optical fiber, and method for manufacturing optical fiber

• US 10,551,307 B2
• Filed: 03/24/2017
• Issued: 02/04/2020
• Est. Priority Date: 03/24/2016
• Status: Active Grant

• Current Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Original Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Inventors: Kohda, Hiroshi, Tachibana, Kumiko, Fujii, Takashi
• Primary Examiner(s): Punnoose, Roy M
• Application Number:
  US16/087,228
• Publication Number:
  US 20190049372A1
• Time in Patent Office: 1,047 Days
• Field of Search: 356337
• CPC Class Codes: C03B 37/027 Fibres composed of different sorts of glass, e.g. glass optical fibresC03B37/0253, C03B37/028 take precedence
• CPC Class Codes: G01M 11/00 Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
• CPC Class Codes: G01N 2021/4735 Solid samples, e.g. paper, glass
• CPC Class Codes: G01N 2021/8444 Fibrous material
• CPC Class Codes: G01N 21/47 Scattering, i.e. diffuse reflection G01N21/25, G01N21/41 take precedence G01N21/55 takes precedence
• CPC Class Codes: G01N 21/892 characterised by the flaw, defect or object feature examined
• CPC Class Codes: G01N 21/896 Optical defects in or on transparent materials, e.g. distortion, surface flaws in conveyed flat sheet or rod for other objects G01N21/958
• CPC Class Codes: G01N 21/952 Inspecting the exterior surface of cylindrical bodies or wires G01N21/956 takes precedence
• CPC Class Codes: G02B 6/02 Optical fibres with cladding with or without a coating
• CPC Class Codes: G02B 6/02395 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 Class Codes: G02B 6/44 Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables cables incorporating electric conductors and optical fibres where features relating to the optical fibres are not of interest H01B11/22

Abstract

An optical fiber inspecting device is disclosed. The optical fiber inspecting device includes a first light-emitting unit that irradiates an optical fiber with a first light beam, the optical fiber including a glass fiber and a coating resin and moving in an axial direction, and a first light-receiving unit that receives scattered light resulting from the first light beam scattered in the optical fiber, and converts the scattered light to an electrical signal. An optical axis of the first light-receiving unit passes through an irradiation position where the first light beam strikes the optical fiber, and the first light beam and the optical axis of the first light-receiving unit diagonally intersect each other, thereby preventing the first light beam from directly entering the first light-receiving unit.

Claims

1. An optical fiber inspecting device comprising:

a first light-emitting unit that irradiates an optical fiber with a first light beam, the optical fiber including a glass fiber and a coating resin and moving in an axial direction; and

a first light-receiving unit that receives scattered light resulting from the first light beam scattered in the optical fiber, and converts the scattered light to an electrical signal,

wherein an optical axis of the first light-receiving unit passes through an irradiation position where the first light beam strikes the optical fiber, and the first light beam and the optical axis of the first light-receiving unit diagonally intersect each other, thereby preventing the first light beam from directly entering the first light-receiving unit;

wherein each light beam and the optical axis of each light-receiving unit corresponding to that light beam intersect each other at an angle in a range of 131°

to 135°

.

2. The optical fiber inspecting device according to claim 1, further comprising:

a second light-emitting unit that irradiates the optical fiber with a second light beam; and

a second light-receiving unit that receives scattered light resulting from the second light beam scattered in the optical fiber, and converts the scattered light to an electrical signal,

wherein an optical axis of the second light-receiving unit passes through an irradiation position where the second light beam strikes the optical fiber, and the second light beam and the optical axis of the second light-receiving unit diagonally intersect each other, thereby preventing the second light beam from directly entering the second light-receiving unit, and

wherein a position irradiated with the first light beam from the first light-emitting unit and a position irradiated with the second light beam from the second light-emitting unit are different each other along the axial direction of the optical fiber.

3. The optical fiber inspecting device according to claim 2, further comprising a computing unit that synthesizes signal waveforms of the electrical signals from the light-receiving units.

4. The optical fiber inspecting device according to claim 1, further comprising:

a third light-emitting unit that irradiates the optical fiber with a third light beam; and

a third light-receiving unit that receives scattered light resulting from the third light beam scattered in the optical fiber, and converts the scattered light to an electrical signal,

wherein an optical axis of the third light-receiving unit passes through an irradiation position where the third light beam strikes the optical fiber, and the third light beam and the optical axis of the third light-receiving unit diagonally intersect each other, thereby preventing the third light beam from directly entering the third light-receiving unit, and

wherein output wavelengths of the first light beam and the third light beam are different each other, and each of first light-receiving unit and the third light-receiving unit includes a wavelength filter transmitting an output wavelength of the corresponding light-emitting unit and blocking an output wavelength of the other light-emitting unit.

5. The optical fiber inspecting device according to claim 1, further comprising:

a fourth light-emitting unit that irradiates the optical fiber with a fourth light beam; and

a fourth light-receiving unit that receives scattered light resulting from the fourth light beam scattered in the optical fiber, and converts the scattered light to an electrical signal,

wherein an optical axis of the fourth light-receiving unit passes through an irradiation position where the fourth light beam strikes the optical fiber, and the fourth light beam and the optical axis of the fourth light-receiving unit diagonally intersect each other, thereby preventing the fourth light beam from directly entering the fourth light-receiving unit, and

wherein a position of the first light-emitting unit and a position of the fourth light-emitting unit with respect to the optical fiber along a circumferential direction are different each other.

6. The optical fiber inspecting device according to claim 5, comprising:

a fifth light-emitting unit that irradiates the optical fiber with a fifth light beam; and

a fifth light-receiving unit that receives scattered light resulting from the fifth light beam scattered in the optical fiber, and converts the scattered light to an electrical signal,

wherein an optical axis of the fifth light-receiving unit passes through an irradiation position where the fifth light beam strikes the optical fiber, and the fifth light beam and the optical axis of the fifth light-receiving unit diagonally intersect each other, thereby preventing the light beam from directly entering the fifth light-receiving unit, and

wherein a position of the first light-emitting unit, a position of the fourth light-emitting unit, and a position of the fifth light-emitting unit with respect to the optical fiber along a circumferential direction are different each other.

7. The optical fiber inspecting device according to claim 1, wherein an output wavelength of light emitted from each light-emitting unit corresponds to non-visible light.

8. The optical fiber inspecting device according to claim 7, wherein an output wavelength of light emitted from each light-emitting unit corresponds to infrared light or ultraviolet light.

9. An optical fiber manufacturing apparatus comprising:

a drawing furnace that draws a glass fiber from a glass preform;

a resin coating unit that coats the glass fiber with a primary resin and a secondary resin;

a resin curing unit that cures the primary resin and the secondary resin; and

the optical fiber inspecting device according to claim 1, that inspects the optical fiber extending from the resin curing unit.

10. A method for inspecting an optical fiber comprising:

irradiating the optical fiber with a first light beam by using the first light-emitting unit of the optical fiber inspecting device according to claim 1, the optical fiber including a glass fiber and a coating resin and moving in an axial direction;

receiving scattered light resulting from the first light beam scattered in the optical fiber, and converting the received scattered light to an electrical signal, by using the first light-receiving unit of the optical fiber inspecting device; and

measuring presence of an air bubble or an internal existing rate of an air bubble in the optical fiber by comparing the electrical signal indicating the amount of incident light on the first light-receiving unit or a rate of change in the amount of the incident light with a predetermined threshold.

11. A method for manufacturing an optical fiber comprising:

drawing a glass fiber from a glass preform;

coating the glass fiber with a primary resin and a secondary resin;

curing the primary resin and the secondary resin; and

inspecting an optical fiber where the resins are cured and the fiber is extended, by using the optical fiber inspecting device according to claim 1; and

winding up the optical fiber.