METHOD AND SYSTEM FOR FABRICATING AN OPTICAL FIBER DEVICE FOR SHAPE SENSING

• US 20200132926A1
• Filed: 10/29/2019
• Published: 04/30/2020
• Est. Priority Date: 10/29/2018
• Status: Active Grant

• Current Assignee: Polyvalor LP
• Original Assignee: Polyvalor LP
• Inventors: KASHYAP, Raman, LORANGER, Sebastien, MONET, Frederic, KADOURY, Samuel, LORRE, Pierre
• Granted Patent: US 11,249,248 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 6/0208 characterised by their structure, wavelength response G02B6/02114, G02B6/02171, G02B6/02195 take precedence; multiple layer cores or claddings G02B6/036, protective coverings G02B6/4429
• CPC Class Codes: G02B 6/02142 based on illuminating or irradiating an amplitude mask, i.e. a mask having a repetitive intensity modulating pattern
• CPC Class Codes: G02B 6/02347 Longitudinal structures arranged to form a regular periodic lattice, e.g. triangular, square, honeycomb unit cell repeated throughout cladding
• CPC Class Codes: G02B 6/06 the relative position of the fibres being the same at both ends, e.g. for transporting images
• CPC Class Codes: G02B 6/4266 Thermal aspects, temperature control or temperature monitoring thermal aspect of electrical circuits H05K7/20, H05K5/0213, temperature control in general G05D23/19
• CPC Class Codes: G02B 6/4415 Cables for special applications G02B6/4429, G02B6/4439, G02B6/4479 take precedence
• CPC Class Codes: G02B 6/4471 Terminating devices demountable connectors G02B6/3807; Cable clamps

Abstract

There is described a method of fabricating an optical fiber device, the method comprising: positioning longitudinal portions of a plurality of optical fibers alongside each other in a given geometrical relationship, depositing liquid coating material around the longitudinal portions of the plurality of optical fibers; and the liquid coating material setting up around the longitudinal portions of the plurality of optical fibers thereby maintaining said given geometrical relationship along the longitudinal portions.

Claims

1. A method of fabricating an optical fiber device, the method comprising:

positioning longitudinal portions of a plurality of optical fibers alongside each other in a given geometrical relationship, depositing liquid coating material around the longitudinal portions of the plurality of optical fibers; and

the liquid coating material setting up around the longitudinal portions of the plurality of optical fibers thereby maintaining said given geometrical relationship along the longitudinal portions.

2. The method of claim 1 wherein said depositing includes extruding the liquid coating material around the longitudinal portions of the plurality of optical fibers while maintaining said given geometrical relationship.

3. The method of claim 2 wherein said extruding includes forcing the liquid coating material at a longitudinal position around the longitudinal portions of the plurality of optical fibers and moving the longitudinal portions of the plurality of optical fibers longitudinally during said forcing.

4. The method of claim 3 wherein said moving includes longitudinally pulling on ends of the plurality of optical fibers.

5. The method of claim 3 wherein said moving is performed as the longitudinal portions of the plurality of optical fibers are longitudinally received in an opening having an inner surface confining the plurality of optical fibers into the given geometrical relationship.

6. The method of claim 5 wherein the inner surface of the opening has a dimension below 1 mm, preferably below 500 μ

m and more preferably below 400 μ

m.

7. The method of claim 1 wherein said depositing includes maintaining the plurality of optical fibers parallel to one another.

8. The method of claim 1 wherein said depositing includes melting coating material thereby forming the liquid coating material, and wherein said setting up includes cooling the liquid coating material.

9. The method of claim 1 further comprising, prior to said depositing, heating a plurality of optical fiber preforms, and drawing the plurality of optical fiber preform into the plurality of optical fibers.

10. The method of claim 9 further comprising, after said drawing, inscribing one or more optical gratings along a portion of each of the plurality of optical fibers.

11. The method of claim 10 wherein at least one of the optical gratings has a random continuous distribution such that a return signal propagating in said optical fiber has a full width at half maximum bandwidth ranging between about 0.1 THz and about 40 THz.

12. The method of claim 1 wherein said positioning include positioning at least an additional component relative to the plurality of optical fibers, said depositing including depositing liquid coating material also around said additional component, the liquid coating material setting up around the additional component as well.

13. A distributed temperature and strain sensing (DTSS) system comprising:

an optical interrogator;

an optical coupler assembly having an input being optically coupled to the optical interrogator and a plurality of outputs; and

a plurality of optical fiber devices having at least;

a first optical fiber device having a first sensing optical fiber being serially connected to a first one of the plurality of outputs of the optical coupler assembly; and

a second optical fiber device having an optical path extender being serially connected to a second one of the plurality of outputs of the optical coupler assembly, the optical path extender having an optical path length being equal to or greater than an optical path length of the first optical fiber device, and a second sensing optical fiber being serially connected to the optical path extender;

wherein, during use, the optical interrogator is configured for emitting an optical signal at the input of the optical coupler assembly, and for receiving, in response to said emitting, a first return optical signal returning from the first sensing optical fiber and a second return optical signal returning from the second sensing optical fiber, the first and second return optical signal being temporally delayed from one another due to the difference in their corresponding optical path lengths.

14. The DTSS system of claim 13 further comprising a third optical fiber device having an optical path extender being serially connected to a third one of the plurality of outputs of the optical coupler assembly, the optical path extender of the third optical fiber device having an optical path length being equal to or greater than an optical path length of the second optical fiber device, and a third sensing optical fiber being serially connected to the optical path extender of the third optical fiber device;

wherein, during use, the optical interrogator is configured for receiving a third return signal returning from the third sensing fiber, the first, second and third return signal being temporally delayed from one another.

15. The DTSS system of claim 14 further comprising a fourth optical fiber device having an optical path extender being serially connected to a fourth one of the plurality of outputs of the optical coupler assembly, the optical path extender of the fourth optical fiber device having an optical path length being equal to or greater than an optical path length of the third optical fiber device, and a fourth sensing optical fiber being serially connected to the optical path extender of the fourth optical fiber device;

wherein, during use, the optical interrogator is configured for receiving a fourth return signal returning from the fourth sensing fiber, the first, second, third and fourth return signal being temporally delayed from one another.

16. The DTSS system of claim 13 wherein at least one of the first and second sensing optical fibers has a scatter increasing device being configured for increasing scattering of the corresponding optical signal as it propagates along the at least one of the first and second sensing optical fibers.

17. The DTSS system of claim 16, wherein the scatter increasing device is an optical grating inscribed along a portion of a corresponding one of the first and second sensing optical fibers, the optical grating having a random continuous distribution such that a return signal, caused by propagation of an optical signal therealong, has a full width at half maximum bandwidth ranging between about 0.1 THz and about 40 THz.

18. The DTSS system of claim 17 wherein said full width at half maximum bandwidth ranges between about 0.35 THz and about 7 THz.

19. The optical device of claim 17 wherein the grating has a coherence length ranging between about 2λ

and about 500λ

when the return signal has a scattering spectrum with a Gaussian shape, wherein λ

denotes a wavelength of the optical signal.

20. The DTSS system of claim 13 wherein the optical coupler assembly is a one-by-two fiber coupler.

21. The DTSS system of claim 13 wherein the optical coupler assembly has one or more a X-by-Y fiber couplers, wherein X and Y are positive integers.

22. The DTSS system of claim 13 wherein the optical coupler assembly has a plurality of two-by-two fiber couplers being connected to one another.

23. An optical device comprising:

a length of optical fiber configured for propagating an optical signal; and

an optical grating inscribed along a portion of the length of optical fiber, the optical grating having a random continuous distribution such that a return signal caused by said propagating has a full width at half maximum bandwidth ranging between about 0.1 THz and about 40 THz.

24. The optical device of claim 23 wherein said full width at half maximum bandwidth ranges between about 0.35 THz and about 7 THz.

25. The optical device of claim 23 wherein the grating has a coherence length ranging between about 2λ

and about 500λ

when the return signal has a scattering spectrum with a Gaussian shape, wherein λ

denotes a wavelength of the optical signal.

26. The optical device of claim 23 wherein the random continuous distribution is a random phase distribution.

27. The optical device of claim 23 wherein the random continuous distribution is a random period distribution.

28. The optical device of claim 23 wherein the random continuous distribution is a random amplitude distribution.

29. The optical device of claim 23 wherein the random continuous distribution is one or more from the group consisting of:

a random phase distribution, a random period distribution and a random amplitude distribution.

30. The optical device of claim 23 wherein the optical grating has a length being at least in the centimeter range.