# US 7,609,928 B2 · Method of connecting optical fibers

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- Number: US 7,609,928 B2
- Document ID: US7609928B2
- Status: Granted
- Kind: B2
- Application number: 12/176,487
- Filed: 2008-07-21
- Published: 2009-03-26
- Granted: 2009-10-27
- Earliest claimed: 2007-08-27
- Assignees: Furukawa Electric Co., Ltd.
- Inventors: Katsunori Imamura
- Web page: https://patentgrep.com/patent/US7609928B2

## CPC

- G02B 6/2551: {using thermal methods, e.g. fusion welding by arc discharge, laser beam, plasma torch}
- G02B 6/02314: {Plurality of longitudinal structures extending along optical fibre axis, e.g. holes}
- G02B 6/02376: {Longitudinal variation along fibre axis direction, e.g. tapered holes}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

A method of connecting a holey fiber to an optical fiber includes fusion splicing an end surface of the holey fiber and an end surface of the optical fiber thereby forming a joint section; and stretching the joint section while heating by pulling the holey fiber and the optical fiber away from each other in a longitudinal direction until an outer diameter of the joint section attains a predetermined value.

## Claims

### Claim 1

A method of connecting a holey fiber to an optical fiber, the holey fiber includes a first core region and a first cladding region surrounding the first core region and having air holes arranged around the first core region, and the optical fiber includes at least a second core region and a second cladding region surrounding the second core region, the method comprising:
fusion splicing an end surface of the holey fiber and an end surface of the optical fiber thereby forming a joint section; and
stretching the joint section while heating by pulling the holey fiber and the optical fiber away from each other in a longitudinal direction until an outer diameter of the joint section attains a predetermined value.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the stretching is performed such that the joint section is pulled until the outer diameter of the joint section attains substantially same outer diameter of the first core region of the holey fiber.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the optical fiber is a holey fiber in which the second cladding region has a plurality of air holes.

### Claim 4 (depends on 1)

The method according to claim 1, further comprising forming a protection member that covers at least the joint section stretched at the stretching.

### Claim 5 (depends on 4)

The method according to claim 4, wherein the forming includes coating the joint section with a resin having a lower refractive index than that of the joint section.

### Claim 6 (depends on 4)

The method according to claim 4, wherein the forming includes accommodating the joint section into a protection sleeve and heating the protection sleeve whereby the protection sleeve is fixed to the joint section.