Optical fiber with inverse triangular trench design

Patent metadata

Field	Value
Publication number	US-2022011503-A1
Application number	US-202117362101-A
Country	US
Kind code	A1
Filing date	Jun 29, 2021
Priority date	Jul 7, 2020
Publication date	Jan 13, 2022
Grant date	—

Abstract

A single mode optical fiber is provided that includes a core region having an outer radius ri and a maximum relative refractive index Δ1max. The single mode optical fiber further includes a cladding region surrounding the core region, the cladding region includes a depressed-index cladding region, a relative refractive index Δ3 of the depressed-index cladding region increasing with increased radial position. The single mode optical fiber has a bend loss at 1550 nm for a 15 mm diameter mandrel of less than about 0.75 dB/turn, a bend loss at 1550 nm for a 20 mm diameter mandrel of less than about 0.2 dB/turn, and a bend loss at 1550 nm for a 30 mm diameter mandrel of less than 0.005 dB/turn. Additionally, the single mode optical fiber has a mode field diameter of 9.0 microns or greater at 1310 nm wavelength.

First claim

What is claimed is:

1 . A single mode optical fiber comprising:
a core region having an outer radius r 1 and a maximum relative refractive index Δ 1max ; and a cladding region surrounding the core region, the cladding region comprising a depressed-index cladding region such that a relative refractive index Δ 3 of the depressed-index cladding region increases with increased radial position, wherein the single mode optical fiber has a bend loss at 1550 nm for a 15 mm diameter mandrel of less than about 0.75 dB/turn, a bend loss at 1550 nm for a 20 mm diameter mandrel of less than about 0.20 dB/turn, and a bend loss at 1550 nm for a 30 mm diameter mandrel of less than 0.005 dB/turn, and wherein the single mode optical fiber has a mode field diameter of about 9.0 microns or greater at 1310 nm wavelength.

2 . The single mode optical fiber of claim 1 , wherein the depressed-index cladding region has an inverse triangular shape.

3 . The single mode optical fiber of claim 1 , wherein the single mode optical fiber has a cable cutoff of less than or equal to about 1260 nm.

4 . The single mode optical fiber of claim 1 , wherein the mode field diameter is about 9.1 microns or greater.

5 . The single mode optical fiber of claim 4 , wherein the mode field diameter is about 9.2 microns or greater.

6 . The single mode optical fiber of claim 1 , wherein the mode field diameter is less than about 9.6 microns.

7 . The single mode optical fiber of claim 1 , wherein the optical fiber cable has zero dispersion wavelength between about 1300 nm and about 1324 nm.

8 . The single mode optical fiber of claim 1 , wherein the bend loss at 1550 nm for a 15 mm diameter mandrel is less than about 0.50 dB/turn.

9 . The single mode optical fiber of claim 8 , wherein the bend loss at 1550 nm for a 15 mm diameter mandrel is less than about 0.25 dB/turn.

10 . The single mode optical fiber of claim 1 , wherein the bend loss at 1550 nm for a 20 mm diameter mandrel is less than about 0.15 dB/turn.

11 . The single mode optical fiber of claim 10 , wherein the bend loss at 1550 nm for a 20 mm diameter mandrel is less than about 0.10 dB/turn.

12 . The single mode optical fiber of claim 1 , wherein the bend loss at 1550 nm for a 30 mm diameter mandrel is less than about 0.0035 dB/turn.

13 . The single mode optical fiber of claim 12 , wherein the bend loss at 1550 nm for a 30 mm diameter mandrel is less than about 0.0030 dB/turn.

14 . The single mode optical fiber of claim 1 , wherein the core region has an alpha value of less than or equal to about 5.

15 . The single mode optical fiber of claim 1 , wherein the core region has an alpha value of greater than or equal to about 10.

16 . The single mode optical fiber of claim 1 , wherein the depressed-index cladding region has a volume V 3 in a range of about 40.0% Δ-micron 2 to about 95.0% Δ-micron 2 .

17 . The single mode optical fiber of claim 1 , wherein the depressed-index cladding region has a volume V 3a , which is defined by a first radial position at an inner radius of the depressed-index cladding region and a second radial position at 20 microns, in a range of about 20.0% Δ-micron 2 to about 70.0% Δ-micron 2 .

18 . A method of making a single mode optical fiber, the method comprising:
providing an overclad assembly that forms a hollow central channel; inserting a consolidated core assembly into the central channel to form a core-cladding assembly such that a gap is disposed between the consolidated core assembly and the overclad assembly; and heating the core-cladding assembly while flowing a down-dopant precursor into the gap to provide a depressed-index cladding region in a cladding region of the optical fiber, a relative refractive index Δ 3 of the depressed-index cladding region increasing with increased radial position.

19 . The method of claim 18 , wherein the depressed-index cladding region has an inverse triangular shape.

20 . The method of claim 18 , wherein the down-dopant comprises at least one of SiF 4 , C 2 F 6 , CF 4 , SF 6 , or combinations thereof.

Assignees

• Corning Inc

Inventors

• Li Ming-Jun
• Tandon Pushkar

Classifications

• G02B6/4403

  with ribbon structure (G02B6/4429, G02B6/4439, G02B6/4479 take precedence) · CPC title

• G02B6/02347 Primary

  Longitudinal structures arranged to form a regular periodic lattice, e.g. triangular, square, honeycomb unit cell repeated throughout cladding · CPC title

• G02B6/03622

  having 2 layers only · CPC title

• G02B6/0365

  arranged - - + · CPC title

• G02B6/0286 Primary

  Combination of graded index in the central core segment and a graded index layer external to the central core segment (G02B6/0288 takes precedence) · CPC title