# US 2023/0056098 A1 · Fiber structure, optical combiner, laser light source, and laser device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2023/0056098 A1
- Document ID: US20230056098A1
- Status: Published application
- Kind: A1
- Application number: 17/790,671
- Filed: 2020-12-06
- Published: 2023-02-23
- Earliest claimed: 2020-02-17
- Assignees: Fujikura Ltd.
- Applicants: Fujikura Ltd.
- Inventors: Akari Takahashi
- Web page: https://patentgrep.com/patent/US20230056098A1

## CPC

- G02B 6/255: Splicing of light guides, e.g. by fusion or bonding
- H01S 5/4012: {Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms}
- G02B 6/4296: {coupling with sources of high radiant energy, e.g. high power lasers, high temperature light sources}
- H01S 3/0675: {Resonators including a grating structure, e.g. distributed Bragg reflectors [DBR] or distributed feedback [DFB] fibre lasers}
- H01S 3/094003: {the pumped medium being a fibre}
- H01S 3/1618: {ytterbium}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL

## Abstract

A fiber structure includes a covering part, the covering part having an optical fiber strand and a coating covering the optical fiber strand; a strand exposed part adjacent to the covering part, the strand exposed part including an exposed optical fiber strand, and a sealing part covering a boundary between the covering part and the strand exposed part. The sealing part including a fluororesin having a structure represented by formula (1): where R represents a divalent organic fluorine compound group, and n represents an integer of 1 or more.

## Claims

### Claim 1

A fiber structure, comprising:
a covering part, the covering part having an optical fiber strand and a coating covering the optical fiber strand,
a strand exposed part adjacent to the covering part, the strand exposed part including an exposed optical fiber strand, and
a sealing part covering a boundary between the covering part and the strand exposed part, the sealing part including a fluororesin having a structure represented by formula (1):
where R represents a divalent organic fluorine compound group, and n represents an integer of 1 or more.

### Claim 2 (depends on 1)

The fiber structure according to claim 1, wherein the divalent organic fluorine compound group is represented by formula (A).
—R5—O— (A)
wherein R5 represents a fluorinated alkylene group having 1 to 5 carbon atoms.

### Claim 3 (depends on 2)

The fiber structure according to claim 2, wherein the fluorinated alkylene group is —CF2—CF(CF3)—, —CF2—, —CF2—CF2— or —CF2—CF2—CF2—.

### Claim 4 (depends on 1)

The fiber structure according to claim 1,
wherein the optical fiber strand has a core and a clad surrounding the core, and
wherein a refractive index of the sealing part is smaller than a refractive index of the clad.

### Claim 5 (depends on 1)

An optical combiner, comprising a first fiber structure and a second fiber structure,
wherein the first fiber structure and the second fiber structure are composed of the fiber structure according to claim 1,
wherein in the first fiber structure, the covering part and the strand exposed part have a plurality of the optical fiber strands,
wherein in the second fiber structure, the covering part and the strand exposed part have one optical fiber strand, and
wherein an end face of the strand exposed part of the first fiber structure and an end face of the strand exposed part of the second fiber structure are fusion-spliced.

### Claim 6 (depends on 5)

The optical combiner according to claim 5, wherein the sealing part has a Young's modulus of 10 MPa or less.

### Claim 7 (depends on 5)

The optical combiner according to claim 5, further comprising:
a housing part housing the first fiber structure and the second fiber structure,
a first fixing part fixing the first fiber structure to the housing part, and
a second fixing part fixing the second fiber structure to the housing part,
wherein in the first fiber structure, the first fixing part is adhered to the sealing part,
wherein in the second fiber structure, the second fixing part is adhered to the sealing part, and
wherein the first fixing part and the second fixing part each have an adhesive strength larger than that of the sealing part with respect to the housing part.

### Claim 8 (depends on 5)

The optical combiner according to claim 5,
wherein the sealing part of the first fiber structure is fixed to the housing part, and the sealing part of the second fiber structure is fixed to the housing part.

### Claim 9 (depends on 5)

A laser light source, comprising:
the optical combiner according to claim 5,
an optical resonance part emitting light of a specific wavelength as a laser light on basis of light emitted from the optical fiber strand of the second fiber structure of the optical combiner, and
an excitation light source making excitation light incident on each of a plurality of the optical fiber strands of the first fiber structure of the optical combiner.

### Claim 10 (depends on 5)

A laser device, comprising:
a plurality of laser light sources, and
an other optical combiner coupling and emitting a laser light made incident from the plurality of laser light sources,
wherein the other optical combiner includes the optical combiner according to claim 5.

### Claim 11 (depends on 10)

The laser device according to claim 10, wherein each of the laser light sources comprises:
the optical combiner,
an optical resonance part emitting light of a specific wavelength as a laser light on basis of light emitted from the optical fiber strand of the second fiber structure of the optical combiner, and
an excitation light source making excitation light incident on each of a plurality of the optical fiber strands of the first fiber structure of the optical combiner.