In-service monitoring of a fiberoptic network

• US 9,571,189 B2
• Filed: 03/04/2016
• Issued: 02/14/2017
• Est. Priority Date: 10/23/2013
• Status: Active Grant

• Current Assignee: Lumentum Operations, LLC (Lumentum Holdings Inc.)
• Original Assignee: Lumentum Operations, LLC (Lumentum Holdings Inc.)
• Inventors: Lin, Yuan, Kim, Brian Sungwan, Parry, John
• Primary Examiner(s): DOBSON, DANIEL G
• Application Number:
  US15/061,300
• Publication Number:
  US 20160191154A1
• Time in Patent Office: 347 Days
• US Class Current: 1/1
• CPC Class Codes: H04B 10/071 using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
• CPC Class Codes: H04B 10/07957 Monitoring or measuring wavelength
• CPC Class Codes: H04B 10/548 Phase or frequency modulation

Abstract

An optical fiber breakage point may be located by coupling to the optical fiber an out-of-band optical test signal modulated at a periodic modulation pattern. A distance to the breakage point may be determined from a difference between modulation patterns of transmitted and received test signals.

Claims

1. A system comprising:

a controller configured to;

determine a magnitude of a returning optical test signal;

determine a modulation frequency offset of the returning optical test signal relative to a current value of a periodically swept modulation frequency; and

detect fault information in a fiberoptic link based on a comparison of at least one of;

the determined magnitude of the returning optical test signal and a reference magnitude of an optical test signal redirected by a wavelength-selective reflector;

or

a comparison between the determined modulation frequency offset of the returning optical test signal to a reference modulation frequency offset of the optical test signal.

2. The system of claim 1, further comprising:

a photodetector to detect the returning optical test signal.

3. The system of claim 1, where the controller is further configured to:

detect, based on the determined modulation frequency offset of the returning optical test signal being less than the reference modulation frequency offset of the optical test signal, that there is a break in the fiberoptic link.

4. The system of claim 1, where the controller is further configured to:

detect, based on the determined magnitude of the returning optical test signal being less than the reference magnitude of the optical test signal, that there is a deterioration in the fiberoptic link.

5. The system of claim 1, where the wavelength-selective reflector is optically coupled to the fiberoptic link.

6. The system of claim 1, where

the wavelength-selective reflector is configured to redirect the optical test signal at a first wavelength, and

the first wavelength is a test wavelength.

7. The system of claim 6, where the wavelength-selective reflector is configured to propagate an information signal, at a second wavelength, to an antenna.

8. The system of claim 1, where

the returning optical test signal is a first returning optical test signal,

the fiberoptic link is a first fiberoptic link, and

controller is further configured to:

determine a magnitude of a second returning optical test signal;

determine a modulation frequency offset of the second returning optical test signal relative to a current value of a periodically swept modulation frequency; and

detect fault information in a second fiberoptic link.

9. The system of claim 8, where the controller, when detecting the fault information in the second fiberoptic link, is configured to:

detect the fault information in the second fiberoptic link, based on a comparison of at least one of;

the determined magnitude of the second returning optical test signal and the reference magnitude of the optical test signal;

or

a comparison between the determined modulation frequency offset of the second returning optical test signal to a reference modulation frequency offset of the optical test signal.

10. The system of claim 1, where the returning optical test signal is based on a test signal that is modulated at the periodically swept modulation frequency.

11. A method comprising:

determining, by a controller, a magnitude of a returning optical test signal;

determining, by the controller, a modulation frequency offset of the returning optical test signal relative to a current value of a periodically swept modulation frequency; and

detecting, by the controller, fault information in a fiberoptic link based on a comparison of at least one of;

the determined magnitude of the returning optical test signal and a reference magnitude of an optical test signal redirected by a wavelength-selective reflector;

or

a comparison between the determined modulation frequency offset of the returning optical test signal to a reference modulation frequency offset of the optical test signal.

12. The method of claim 11, further comprising:

detecting the returning optical test signal.

13. The method of claim 11, further comprising:

detecting, based on the determined modulation frequency offset of the returning optical test signal being less than the reference modulation frequency offset of the optical test signal, that there is a break in the fiberoptic link.

14. The method of claim 11, further comprising:

detecting, based on the determined magnitude of the returning optical test signal being less than the reference magnitude of the optical test signal, that there is a deterioration in the fiberoptic link.

15. The method of claim 11, where the wavelength-selective reflector is optically coupled to the fiberoptic link.

16. The method of claim 11, where

the wavelength-selective reflector is configured to redirect the optical test signal at a first wavelength, and

the first wavelength is a test wavelength.

17. The method of claim 16, further comprising:

propagating an information signal, at a second wavelength, to an antenna.

18. The method of claim 11, where

the returning optical test signal is a first returning optical test signal,

the fiberoptic link is a first fiberoptic link, and

the method further comprises:

determining a magnitude of a second returning optical test signal;

determining a modulation frequency offset of the second returning optical test signal relative to a current value of a periodically swept modulation frequency; and

detecting fault information in a second fiberoptic link.

19. The method of claim 18, where detecting the fault information in the second fiberoptic link includes:

detecting the fault information in the second fiberoptic link, based on a comparison of at least one of;

the determined magnitude of the second returning optical test signal and the reference magnitude of the optical test signal;

or

a comparison between the determined modulation frequency offset of the second returning optical test signal to a reference modulation frequency offset of the optical test signal.

20. The method of claim 11, where the returning optical test signal is based on a test signal that is modulated at the periodically swept modulation frequency.