Fiber module

Patent metadata

Field	Value
Publication number	US-11237334-B2
Application number	US-201916979626-A
Country	US
Kind code	B2
Filing date	Feb 28, 2019
Priority date	Mar 13, 2018
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

A fiber module (1B) according to the present disclosure includes an input-side optical fiber (11), an output-side optical fiber (12), a ferrule (20) in which the input-side optical fiber and the output-side optical fiber are insertable in both ends and a groove (32) is formed in a direction orthogonal to a longitudinal direction (D1) in the middle of the longitudinal direction, a dielectric multilayer film filter (30) inserted in the groove, and an input-side GI fiber (15) and an output-side GI fiber (16) joined by fusion to respective terminal portions of the input-side optical fiber and the output-side optical fiber. The dielectric multilayer film filter is interposed between an end surface (15f) of the input-side GI fiber and an end surface (16f) of the output-side GI fiber in the longitudinal direction.

First claim

The invention claimed is:

1. A fiber module comprising:
an input-side optical fiber;
an output-side optical fiber;
a ferrule in which the input-side optical fiber and the output-side optical fiber are insertable in both ends and includes a V-shaped groove formed in a direction orthogonal to a longitudinal direction;
a dielectric multilayer film filter inserted in the V-shaped groove and arranged inclined at greater than or equal to 5° and less than or equal to 10° with respect to a plane orthogonal to an optical axis; and
an input-side graded index fiber and an output-side graded index fiber joined by fusion to respective terminal portions of the input-side optical fiber and the output-side optical fiber, wherein
the dielectric multilayer film filter is interposed between an end surface of the input-side graded index fiber and an end surface of the output-side graded index fiber in the longitudinal direction, and
the end surface of each of the input-side graded index fiber and the output-side graded index fiber abuts the dielectric multilayer film filter while the dielectric multilayer film is inclined at greater than or equal to 5° and less than or equal to 10° with respect to the plane orthogonal to the optical axis and are optically polished.

2. The fiber module according to claim 1 , wherein
a length of the input-side graded index fiber is such that luminous flux emitted from an end surface of the input-side optical fiber forms a beam waist at a position of the dielectric multilayer film filter, and
a length of the output-side graded index fiber is such that luminous flux passing through the dielectric multilayer film filter is coupled to the output-side optical fiber at a predetermined coupling efficiency.

3. The fiber module according to claim 1 , wherein
the dielectric multilayer film filter is fitted in a bottom portion of the V-shaped groove.

4. The fiber module according to claim 1 , wherein the dielectric multilayer film filter includes a thin-film portion that is thinner than a surrounding part.

5. The fiber module according to claim 1 , wherein an extending direction of the V-shaped groove forms an angle of greater than or equal to 80° and less than or equal to 90° with respect to the longitudinal direction of the ferrule.

6. The fiber module according to claim 1 , wherein the ferrule is made of zirconia.

7. The fiber module according to claim 1 wherein the dielectric multilayer film filter is fixed within the V-shaped groove using an optical adhesive.

8. The fiber module according to claim 1 wherein the dielectric multilayer film includes a thinned polyimide film disposed on one of a quartz substrate, a glass substrate, and a silicon substrate,
wherein a first thickness of the thinned polyimide film is less than a second thickness of the polyimide film at formation on the one of the quartz, glass, and silicon substrate.

9. The fiber module according to claim 8 wherein the second thickness is approximately 1 micrometer.

10. The fiber module according to claim 8 wherein the dielectric multilayer film further includes a photoresist applied on the polyimide film.

11. The fiber module according to claim 1 wherein refractive indexes of cores of the input-side graded index fiber, the output-side graded index fiber, and the dielectric multilayer film are approximately 1.5.

12. The fiber module according to claim 1 wherein the dielectric multilayer film includes an oxide film.

Assignees

• Nippon Telegraph & Telephone

Inventors

• Horikoshi Kengo
• Yamada Takashi
• Yoshinaga Hisao
• Kanai Shunsuke
• Kubota Manabu

Classifications

• G02B6/2937 Primary

  In line lens-filtering-lens devices, i.e. elements arranged along a line and mountable in a cylindrical package for compactness, e.g. 3- port device with GRIN lenses sandwiching a single filter operating at normal incidence in a tubular package · CPC title

• G02B6/3845

  ferrules comprising functional elements, e.g. filters · CPC title

• G02B6/2552

  reshaping or reforming of light guides for coupling using thermal heating, e.g. tapering, forming of a lens on light guide ends · CPC title

• G02B6/264

  with optical elements between opposed fibre ends which perform a function other than beam splitting (having lens focusing means G02B6/32; utilising prism or grating G02B6/34) · CPC title

• G02B2006/12109

  Filter · CPC title