LIGHT SOURCE ASSEMBLIES AND SYSTEMS AND METHODS WITH MODE HOMOGENIZATION

• US 20180210126A1
• Filed: 01/20/2017
• Published: 07/26/2018
• Est. Priority Date: 01/20/2017
• Status: Active Grant

• Current Assignee: Corning Research & Development Corporation (Corning Incorporated)
• Original Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Inventors: Bauco, Anthony Sebastian
• Granted Patent: US 10,234,614 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 2006/4297 having protection means, e.g. protecting humans against accidental exposure to harmful laser radiation
• CPC Class Codes: G02B 6/0006 Coupling light into the fibre in general G02B6/4298
• CPC Class Codes: G02B 6/0008 the light being emitted at the end of the fibre
• CPC Class Codes: G02B 6/3825 with an intermediate part, e.g. adapter, receptacle, linking two plugs
• CPC Class Codes: G02B 6/421 the intermediate optical component consisting of a short length of fibre, e.g. fibre stub
• CPC Class Codes: G02B 6/4285 Optical modules characterised by a connectorised pigtail
• CPC Class Codes: G02B 6/562 locatable, e.g. using magnetic means

Abstract

A method of generating light for use in tracing an end of a cable assembly includes coupling convergent visible light into an input end of a multimode mode-homogenizing optical fiber having low-order and high-order modes and comprising an output end, a fiber angle, a length and a mode-homogenization length. The inputted light is initially concentrated mainly in the low-order modes. The method also includes conveying the light through the length of the mode-homogenizing optical fiber to form outputted light that is substantially mode-homogenized, substantially spatially uniform and substantially angularly uniform and having a divergence angle that is substantially the same as the fiber angle. Light source assemblies and systems for carrying out the method are also disclosed.

Claims

1. A light source assembly for use with a multimode delivery waveguide having an input end supported by an input connector, comprising:

a housing having an interior and a bulkhead;

a light emitter that resides within the interior of the housing and that emits visible light;

a multimode mode-homogenizing optical fiber that has an input end, an output end, a fiber angle, a length L, and a mode-homogenization length LMH, wherein the input end is optically coupled to the light emitter to receive the visible light at a convergence angle that is less than the fiber angle, and wherein the length L is in the range from (0.8)·

LMH≤

L≤

(1.25)·

LMH so that the output end emits the light at a divergence angle that is substantially the same as the fiber angle;

an output connector at the output end of the mode-homogenizing optical fiber; and

a connector adapter having inner and outer receptacles, with the output connector of the mode-homogenizing optical fiber is configured for engagement with the inner receptacle and wherein the outer receptacle is configured for receiving the input connector of the multimode delivery waveguide.

2. The light source assembly according to claim 1, wherein the connector adapter is located at the bulkhead.

3. The light source assembly according to claim 1, wherein the optical coupling between the light emitter and the input end of the mode-homogenizing optical fiber is performed by a single lens element.

4. The light source assembly according to claim 1, wherein the light emitter comprises a laser.

5. The light source assembly according to claim 1, wherein the mode-homogenizing optical fiber has a radiation length LR and wherein the length L is in the range (0.2)·

LR≤

L≤

(0.3)·

LR.

6. The light-source assembly according to claim 1, wherein the length L is in the range (0.95)·

LMH≤

L≤

(1.05)·

LMH.

7. The light-source assembly according to claim 1, further comprising:

control circuitry electrically connected to the light emitter;

an electrical power source electrically connected to the control circuitry; and

a switch electrically connected to the control circuitry to control the operation of the control circuitry.

8. The light-source assembly according to claim 1, wherein the light emitter has an output power of between 20 and 1000 milliwatts.

9. The light-source assembly according to claim 1, wherein the mode-homogenizing optical fiber comprises a light-diffusing or light-scattering optical fiber.

10. The light-source assembly according to claim 1, further comprising the multimode delivery waveguide, wherein the input connector of the multimode delivery waveguide is operably engaged with the outer receptacle of the connector adapter so that the input end of the multimode delivery waveguide is optically coupled to the output end of the mode-homogenizing optical fiber.

11. The light-source assembly according to claim 10, wherein the delivery waveguide has an output connector coupled thereto and further comprising:

a traceable cable assembly that comprises a cable that supports at least one data element and at least first and second tracer optical fibers respectively, the traceable cable assembly further comprising first and second connectors that respectively terminate first and second opposite ends of the cable, the first and second connectors respectively having first and second receptacles that respectively terminate first and second input ends of the first and second tracer optical fibers, and wherein first and second output ends of the first and second tracer optical fibers respectively terminate at the second and first connectors of the first and second connectors; and

wherein the output connector of the delivery waveguide is operably engaged with one of the first and connector receptacles of one of the first and second connectors of the traceable cable assembly.

12. A light source system for use with a traceable cable assembly terminated by first and second connectors, comprising:

a light emitter that emits light;

a section of multimode mode-homogenizing optical fiber having an input end, an output end, a length L, a mode-homogenization length LMH, and a fiber angle θ

_F, and wherein (0.8)·

LMH≤

L≤

(1.25)·

LMH;

an optical component operably disposed between the light emitter and the input end of the mode-homogenizing optical fiber to couple light into the input end of the mode-homogenizing optical fiber at a convergence angle θ

_C that is less than the fiber angle θ

_F and wherein the output end is supported by an output connector and wherein the output end emits the light at a divergence angle θ

_D in the range (0.9)·

θ

_F≤

θ

_D≤

θ

_F;

a connector adapter having first and second receptacles, wherein the output connector is configured for engagement in the first receptacle; and

a multimode delivery waveguide having an input end terminated by an input connector, wherein the input connector is configured to be operably engaged and disengaged with the second receptacle of the connector adapter.

13. The light source system according to claim 12, wherein the optical component consists of a single lens element.

14. The light source system according to claim 12, wherein the light emitter comprises a laser that emits light at a visible wavelength.

15. The light source system according to claim 12, wherein the mode-homogenizing optical fiber has a radiation length LR and also has an overall length L in the range (0.2)·

LR≤

L≤

(0.3)·

LR.

16. The light-source system according to claim 12, wherein the length L is in the range from (0.95)·

LMH≤

L≤

(1.05)·

LMH.

17. The light-source system according to claim 12, further comprising:

control circuitry electrically connected to the light emitter;

an electrical power source electrically connected to the control circuitry; and

a switch electrically connected to the control circuitry to control the operation of the control circuitry.

18. The light-source system according to claim 12, wherein the mode-homogenizing optical fiber comprises a light-diffusing optical fiber or a light-scattering optical fiber.

19. The light-source system according to claim 12, wherein the multimode delivery waveguide comprises a multimode optical fiber.

20. The light-source system according to claim 12, further comprising an output connector, wherein the multimode delivery waveguide has an output end terminated by the output connector and wherein the output connector is configured to be engaged and disengaged with respective first and second connector receptacles of the first and second connectors of the traceable cable assembly.

21. A method of generating light for use in tracing an end of a cable assembly, comprising:

a) coupling convergent visible light into an input end of a multimode mode-homogenizing optical fiber having low-order and high-order modes and comprising an output end, a fiber angle θ

_F, a length L, and a mode-homogenization length LMH, and wherein the light is initially concentrated in the low-order modes; and

b) conveying the light through the length L of the mode-homogenizing optical fiber to form outputted light that is substantially mode-homogenized, substantially spatially uniform, and substantially angularly uniform and having a divergence angle θ

_D in the range (0.9)·

θ

_F≤

θ

_D≤

θ

_F.

22. The method according to claim 21, wherein (0.8)·

LMH≤

L≤

(1.25)·

LMH.

23. The method according to claim 21, further comprising prior to step a):

emitting the visible light from a light emitter as divergent visible light; and

receiving the divergent visible light at an optical component that converts the divergent visible light into the convergent visible light.

24. The method according to claim 23, wherein the light emitter comprises a laser and wherein the optical component consists of a single lens element operably disposed between the laser and the input end of the mode-homogenizing optical fiber.

25. The method according to claim 21, wherein the length L is in the range from (0.95)·

LMH≤

L≤

(1.05)·

LMH.

26. The method according to claim 21, wherein the mode-homogenizing optical fiber comprises either a light-diffusing or light-scattering optical fiber.

27. The method according to claim 21, further comprising:

delivering the outputted light to an input end of a tracer optical fiber supported by a traceable patch cord.

28. The method according to claim 21, wherein the convergent light does not satisfy an eye safety standard and wherein the outputted light satisfies said eye safety standard.