Rayleigh scattering based distributed fiber sensors with optimized scattering coefficients

Patent metadata

Field	Value
Publication number	US-10663326-B2
Application number	US-201816047582-A
Country	US
Kind code	B2
Filing date	Jul 27, 2018
Priority date	Aug 21, 2017
Publication date	May 26, 2020
Grant date	May 26, 2020

Abstract

A fiber sensor includes an optical fiber configured for operation at a wavelength from about 800 nm to about 1600 nm. The optical fiber includes a cladding that is defined by a fiber outer diameter and a core that is surrounded by the cladding. The core of the optical fiber has a Rayleigh scattering coefficient, αs, that is controlled by controlling a concentration of one or more dopants in the core. The Rayleigh scattering coefficient is tuned to be within a predetermined range of an optimum Rayleigh scattering coefficient for a given total length, L, of the optical fiber. The predetermined range is from about 70% of the optimum αs to about 130% of the optimum αs.

First claim

What is claimed is:

1. A fiber sensor, comprising:
an optical fiber configured for operation at a wavelength from about 800 nm to about 1600 nm, wherein the optical fiber comprises:
a cladding that is defined by a fiber outer diameter; and
a core that is surrounded by the cladding,

wherein the core of the optical fiber has a Rayleigh scattering coefficient, α s , that is tuned to be within a predetermined range of an optimum α s for a given total length, L, of the optical fiber, wherein the optimum α s value is given by:

α
s

=

4.3

2
⁢
L

,

 wherein α s is controlled during manufacture of the optical fiber by controlling a concentration of at least one dopant, the at least one dopant comprising nanoparticles having a diameter of 300 nm or less, the nanoparticles being doped into the core of the optical fiber at a concentration of at least 800/mm 3 , the nanoparticles comprising ZrO 2 , and wherein the predetermined range is from about 70% of the optimum α s , to about 130% of the optimum α s .

2. The fiber sensor of claim 1 , wherein the at least one dopant further comprises GeO 2 at a concentration of at least about 20%.

3. The fiber sensor of claim 1 , wherein the at least one dopant further comprises GeO 2 at a concentration of at least about 30%.

4. The fiber sensor of claim 1 , wherein the at least one dopant further comprises GeO 2 at a concentration of at least about 40%.

5. The fiber sensor of claim 1 , wherein the nanoparticles are doped into the core of the optical fiber at a concentration of at least 850/mm 3 .

6. The fiber sensor of claim 5 , wherein the diameter of the nanoparticles is 100 nm.

7. The fiber sensor of claim 1 , wherein the nanoparticles are doped into the core of the optical fiber at a concentration of at least 1880/mm 3 .

8. The fiber sensor of claim 7 , wherein the diameter of the nanoparticles is 150 nm.

9. The fiber sensor of claim 1 , wherein the nanoparticles are doped into the core of the optical fiber at a concentration of at least 1490/mm 3 .

10. The fiber sensor of claim 9 , wherein the diameter of the nanoparticles is 175 nm.

11. The fiber sensor of claim 1 , wherein the nanoparticles are doped into the core of the optical fiber at a concentration of at least 1350/mm 3 .

12. The fiber sensor of claim 11 , wherein the diameter of the nanoparticles is 200 nm.

13. The fiber sensor of claim 1 , wherein the optical fiber has a graded index profile.

14. The fiber sensor of claim 1 , wherein the optical fiber has a step index profile.

15. The fiber sensor of claim 1 , wherein the optical fiber has a total attenuation of 0.205 dB/km or less.

Assignees

• Corning Inc

Inventors

• Artuso Anthony
• Kozlov Valery A
• Li Ming-Jun

Classifications

• C03C2201/02

  Pure silica glass, e.g. pure fused quartz · CPC title

• G01D5/35361 Primary

  using elastic backscattering to detect the measured quantity, e.g. using Rayleigh backscattering · CPC title

• G02B6/02395

  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

• C03C2214/16

  Microcrystallites, e.g. of optically or electrically active material · CPC title

• C03B37/02718

  Thermal treatment of the fibre during the drawing process, e.g. cooling (coating C03C25/10) · CPC title