Optical device and optical device manufacturing method

Patent metadata

Field	Value
Publication number	US-9977181-B2
Application number	US-201715416169-A
Country	US
Kind code	B2
Filing date	Jan 26, 2017
Priority date	Jul 30, 2014
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

Provided is an optical device whose resin member is less likely to reach a high temperature, as compared with that of a conventional optical device. The optical device ( 1 ) includes (i) an optical fiber ( 11 ) in which a jacket-removed section (I 1 ) is provided and (ii) a resin member ( 12 ) in which the jacket-removed section (I 1 ) is embedded. The jacket-removed section (I 1 ) is a section in which a part of a jacket ( 112 ) covering an outer surface of a cladding ( 111 b ) is removed so that only a part of the outer surface of the cladding ( 111 b ) is exposed in a cross section of the optical fiber ( 11 ).

First claim

The invention claimed is:

1. An optical device, comprising:
an optical fiber in which at least one jacket-removed section is provided; and
a resin member in which the at least one jacket-removed section of the optical fiber is embedded, the resin member having a refractive index higher than a refractive index of a cladding of the optical fiber,
the at least one jacket-removed section being a section in which a jacket covering an outer surface of the cladding has been partially removed so that only a part of the outer surface of the cladding is exposed in a cross section of the optical fiber; and
two cut surfaces of the jacket in the at least one jacket-removed section, between which two cut surfaces a portion of the cladding of the optical fiber which portion is exposed in the at least one jacket-removed section is sandwiched, are located on the same plane.

2. The optical device as set forth in claim 1 , wherein:
a length L of the at least one jacket-removed section is shorter than L0 which is defined by Equation (A) below:
L 0= t /tan(cos −1 (( n 0/ n 1)cos(θ0)))  (A)

where n 0 is the refractive index of the cladding, θ 0 is a critical propagation angle of light that propagates in the cladding, n 1 is the refractive index of the resin member, and t is a thickness of the resin member.

3. The optical device as set forth in claim 1 , wherein:
the at least one jacket-removed section of the optical fiber includes a plurality of jacket-removed sections.

4. The optical device as set forth in claim 3 , wherein:
the plurality of jacket-removed sections include two jacket-removed sections in which the outer surface of the cladding is exposed in identical directions; and
a gap G between the two jacket-removed sections is longer than L0 which is defined by Equation (A) below:
L 0= t /tan(cos −1 (( n 0/ n 1)cos(θ0)))  (A)

where n 0 is the refractive index of the cladding, θ 0 is a critical propagation angle of light that propagates in the cladding, n 1 is the refractive index of the resin member, and t is a thickness of the resin member.

5. The optical device as set forth in claim 3 , wherein:
the outer surface of the cladding is exposed in different directions in adjacent two of the plurality of jacket-removed sections.

6. The optical device as set forth in claim 1 , wherein:
a cut surface of the jacket in an adjacent section adjacent to the at least one jacket-removed section is a flat surface having a normal vector that makes, with a radial direction of the optical fiber, an angle α that satisfies Equation (B) below:
α<cos −1 (( n 0/ n 1)cos(θ0))  (B)

where n 0 is the refractive index of the cladding, θ 0 is a critical propagation angle of light that propagates in the cladding, and n 1 is the refractive index of the resin member.

7. The optical device as set forth in claim 1 , wherein:
the optical fiber includes:
a core which is made of glass;
an inner cladding which is made of glass and covers a side surface of the core;
an outer cladding which is made of resin and covers an outer surface of the inner cladding; and
an outer jacket which is made of resin and covers an outer surface of the outer cladding;

the cladding is the inner cladding; and
the jacket includes the outer cladding and the outer jacket.

8. A method of producing an optical device, comprising the steps of:
forming a jacket-removed section in an optical fiber; and
embedding the jacket-removed section of the optical fiber in a resin member having a refractive index higher than a refractive index of a cladding of the optical fiber,
the jacket-removed section being a section in which a jacket covering an outer surface of the cladding has been partially removed so that only a part of the outer surface of the cladding is exposed in a cross section of the optical fiber; and
two cut surfaces of the jacket in the at least one jacket-removed section, between which two cut surfaces a portion of the cladding of the optical fiber which portion is exposed in the at least one jacket-removed section is sandwiched, being located on the same plane.

9. An optical device, comprising:
an optical fiber in which at least one jacket-removed section is provided; and
a resin member in which the at least one jacket-removed section of the optical fiber is embedded, the resin member having a refractive index higher than a refractive index of a cladding of the optical fiber,
the at least one jacket-removed section being a section in which a jacket covering an outer surface of the cladding has been partially removed so that only a part of the outer surface of the cladding is exposed in a cross section of the optical fiber,
wherein:
a length L of the at least one jacket-removed section is shorter than L0 which is defined by Equation (A) below:
L 0= t /tan(cos −1 (( n 0/ n 1)cos(θ0)))  (A)

where n 0 is the refractive index of the cladding, θ 0 is a critical propagation angle of light that propagates in the cladding, n 1 is the refractive index of the resin member, and t is a thickness of the resin member.

10. An optical device, comprising:
an optical fiber in which at least one jacket-removed section is provided; and
a resin member in which the at least one jacket-removed section of the optical fiber is embedded, the resin member having a refractive index higher than a refractive index of a cladding of the optical fiber,
the at least one jacket-removed section being a section in which a jacket covering an outer surface of the cladding has been partially removed so that only a part of the outer surface of the cladding is exposed in a cross section of the optical fiber,
wherein the at least one jacket-removed section of the optical fiber includes a plurality of jacket-removed sections,
wherein:
the plurality of jacket-removed sections include two jacket-removed sections in which the outer surface of the cladding is exposed in identical directions; and
a gap G between the two jacket-removed sections is longer than L0 which is defined by Equation (A) below:
L 0= t /tan(cos −1 (( n 0/ n 1)cos(θ0)))  (A)

where n 0 is the refractive index of the cladding, θ 0 is a critical propagation angle of light that propagates in the cladding, n 1 is the refractive index of the resin member, and t is a thickness of the resin member.

11. An optical device, comprising:
an optical fiber in which at least one jacket-removed section is provided; and
a resin member in which the at least one jacket-removed section of the optical fiber is embedded, the resin member having a refractive index higher than a refractive index of a cladding of the optical fiber,
the at least one jacket-removed section being a section in which a jacket covering an outer surface of the cladding has been partially removed so that only a part of the outer surface of the cladding is exposed in a cross section of the optical fiber,
wherein:
a cut surface of the jacket in an adjacent section adjacent to the at least one jacket-removed section is a flat surface having a normal vector that makes, with a radial direction of the optical fiber, an angle α that satisfies Equation (B) below:
α<cos −1 (( n 0/ n 1)cos(θ0))  (B)

where n 0 is the refractive index of the cladding, θ 0 is a critical propagation angle of light that propagates in the cladding, and n 1 is the refractive index of the resin member.

Assignees

• Fujikura Ltd

Inventors

• Ikoma Shinya

Classifications

• G02B6/02395 Primary

  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

• G02B6/03622

  having 2 layers only · CPC title

• G02B6/03605

  Highest refractive index not on central axis · CPC title

• G02B6/4296

  coupling with sources of high radiant energy, e.g. high power lasers, high temperature light sources · CPC title

• G02B6/14

  Mode converters · CPC title