Optical fiber defect detection

Patent metadata

Field	Value
Publication number	US-9438335-B2
Application number	US-201414579380-A
Country	US
Kind code	B2
Filing date	Dec 22, 2014
Priority date	Dec 26, 2013
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

An optical data transmitter is operable to transmit data other than test data on an optical fiber at a first wavelength and an optical time domain reflectometer is operable to receive data from the optical fiber at the first wavelength and to use the received data at the first wavelength to determine whether a defect exists in the optical fiber.

First claim

What is claimed is:

1. An optical communication system, comprising:
an optical data transmitter operable to transmit data other than test data on an optical fiber at a first wavelength; and
an optical time domain reflectometer operable to receive data from the optical fiber at the first wavelength, to use the received data at the first wavelength to determine whether a defect exists in the optical fiber, to cross-correlate multiple sets of the received data and transmitted data, and to average the resulting cross-correlation values.

2. The optical communication system of claim 1 , where the optical data transmitter is operable to transmit data at a plurality of wavelengths in addition to the first wavelength.

3. The optical communication system of claim 1 , further comprising:
the optical time domain reflectometer further comprising a correlator operable to cross-correlate the received data and the transmitted data.

4. The optical communication system of claim 3 , where the cross-correlation is done in the frequency domain.

5. The optical communication system of claim 3 , further comprising:
the optical time domain reflectometer further operable to average the resulting cross-correlation values.

6. The optical communication system of claim 3 , further comprising:
an anti-aliasing filter that filters received data before cross-correlation.

7. The optical communication system of claim 3 , further comprising:
a decimator that reduces the amount of transmitted data being cross-correlated.

8. The optical communication system of claim 7 , further comprising:
an anti-aliasing filter that filters transmitted data before decimation.

9. The optical communication system of claim 1 , further comprising:
a controller operable to analyze information from the optical time domain
reflector to determine whether defects exist in the optical fiber.

10. A method for defect detection in an optical fiber, comprising:
transmitting, by an optical data transmitter, data other than test data on an optical fiber at a first wavelength;
receiving, by an optical time domain reflectometer, data on the optical fiber at the first wavelength; and
cross-correlating, by a correlator, multiple sets of the received data and transmitted data; and
determining, by a controller, from the transmitted and received data, whether there is a defect in the optical fiber.

11. The method of claim 10 , further comprising:
analyzing, by the controller, the results of cross-correlation to determine whether there is a defect in the optical fiber.

12. The method of claim 11 , further comprising:
filtering, by an anti-aliasing filter, the received data before cross-correlating.

13. The method of claim 11 , further comprising:
filtering, by an anti-aliasing filter, the transmitted data before cross-correlating.

14. The method of claim 13 , further comprising:
reducing, by a decimator, the filtered transmitted data before cross-correlating.

15. An optical communication system, comprising:
an optical data transmitter operable to transmit data on an optical fiber at a particular wavelength;
an optical time domain reflectometer operable to receive data from the optical fiber at the particular wavelength;
a correlator operable to cross-correlate the received data and the transmitted data; and
the optical communication system further operable to cross-correlate multiple sets of received data and transmitted data and to average the resulting cross-correlation values.

16. The optical communication system of claim 15 , further comprising:
a controller operable to analyze the average of the cross-correlations to determine whether there is a defect in the optical fiber.

17. The optical communication system of claim 15 , where the particular wavelength is also used to transmit data other than test data.

18. The optical communication system of claim 17 , where the particular wavelength is one of a plurality of wavelengths used to transmit data other than test data.

19. The optical communication system of claim 15 , further comprising:
an anti-aliasing filter that filters transmitted data before cross-correlation; and
a decimator that reduces the amount of transmitted data being cross-correlated.

20. The optical communication system of claim 15 , further comprising:
an anti-aliasing filter that filters received data before cross-correlation.

Assignees

• Texas Instruments Inc

Inventors

• Viswanathan Nagarajan

Classifications

• G01M11/3109

  Reflectometers detecting the back-scattered light in the time-domain, e.g. OTDR · CPC title

• H04B10/071 Primary

  using a reflected signal, e.g. using optical time domain reflectometers [OTDR] · CPC title

• G01M11/3118

  using coded light-pulse sequences · CPC title

• G01M11/3127

  using multiple or wavelength variable input source · CPC title