Kerr phase-interrogator for sensing and signal processing applications

Patent metadata

Field	Value
Publication number	US-9500562-B2
Application number	US-201514614510-A
Country	US
Kind code	B2
Filing date	Feb 5, 2015
Priority date	Feb 5, 2015
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

A Kerr medium is introduced into OFDR configuration to enable phase to power variation conversion thereby enabling an all-optical beat signal acquisition, thus eliminating performance limits associated with bandwidth capabilities of electronic and optoelectronic components.

First claim

What is claimed is:

1. A method comprising:
launching an input frequency-swept sinusoidal optical signal into a Kerr phase interrogator,
wherein the input frequency-swept sinusoidal optical signal comprises a first signal portion and a second signal portion,
wherein the first signal portion comprises one or more back reflected signals resulting from propagation of a first frequency-swept sinusoidal optical signal through an optical medium,
wherein the second signal portion comprises a second frequency-swept sinusoidal optical signal,
wherein the first frequency-swept sinusoidal optical signal and the second frequency-swept sinusoidal optical signal are orthogonally polarized; and

extracting information about one or more reflection characteristics of the optical medium from one or more power variations in a frequency-swept sinusoidal optical signal at an output of the Kerr phase interrogator, thereby performing an all-optical Incoherent Optical Frequency Domain Reflectometry.

2. The method of claim 1 , wherein the first signal portion and the second signal portion have identical frequencies.

3. The method of claim 1 , wherein the first signal portion and the second signal portion that oscillate at two different frequencies.

4. The method of claim 1 , wherein the Kerr phase interrogator comprise a Kerr medium.

5. The method of claim 4 , wherein the Kerr medium comprise a length of fiber with low chromatic dispersion.

6. The method of claim 5 , wherein the Kerr medium comprise an approximately 4 km long fiber with a chromatic dispersion of approximately 3 ps/nm-km.

7. The method of claim 1 , wherein the one or more back reflected signals resulting from propagation of the first frequency-swept sinusoidal optical signal through the optical medium are combined with the second signal portion using a fiber-coupled polarization beam combiner.

8. The method of claim 1 wherein the optical medium comprises an optical fiber.

9. The method of claim 8 wherein the optical fiber is terminated with a reflector.

10. The method of claim 1 wherein an optical circulator is used for launching the first frequency-swept sinusoidal optical signal into the optical medium.

11. The method of claim 1 wherein the orthogonally polarized first and the second frequency-swept sinusoidal optical signals are generated using a CW laser modulated with a frequency-swept sinusoidal electrical signal and split using a fiber-coupled polarization beam splitter.

12. The method of claim 1 wherein the output of the Kerr phase interrogator is filtered with a band-pass filter to isolate one or more side-band power signals from the output of the Kerr phase interrogator.

13. The method of claim 12 wherein the band-pass filter has a bandwidth of approximately 3 GHz.

14. The method of claim 12 wherein the output of the band-pass filter is detected and measured using a photodetector and an external measurement device.

15. The method of claim 1 wherein the frequency-swept sinusoidal optical signal is amplified with an Erbium-doped fiber amplifier (EDFA) prior to launching into the Kerr phase interrogator.

16. An apparatus comprising:
a Kerr phase interrogator configured to receive an input frequency-swept sinusoidal optical signal,
wherein the input frequency-swept sinusoidal optical signal comprises two orthogonally polarized frequency-swept sinusoidal optical signal portions with one or more relative phase variations; and
a loss device for isolating one or more power variations in a frequency-swept sinusoidal optical signal at an output of the Kerr phase interrogator,
wherein, the one more power variations in the frequency-swept sinusoidal optical signal at the output of the Kerr phase interrogator correspond to the one or more phase variations in the input frequency-swept sinusoidal optical signal.

17. The apparatus of claim 16 , wherein the loss device comprise a band-pass filter with bandwidth of approximately 3 GHz.

18. The apparatus of claim 16 wherein the input frequency-swept sinusoidal optical signal comprising two orthogonally polarized frequency-swept sinusoidal optical signal portions with one or more relative phase variations is produced by splitting a source frequency-swept sinusoidal optical signal into a first signal portion and a second signal portion, wherein the first signal portion and the second signal portion are orthogonally polarized, launching the first signal portion into an optical medium and combining a resulting one or more back reflections with the second signal portion to thereby produce the input frequency-swept sinusoidal optical signal comprising two orthogonally polarized frequency-swept sinusoidal optical signal portions with relative phase variations.

19. The apparatus of claim 18 wherein a fiber-coupled polarization beam splitter is used to split the source frequency-swept sinusoidal optical signal into the first signal portion and the second signal portion, wherein the first and the second signal portions are orthogonally polarized.

20. The apparatus of claim 18 wherein an optical circulator is used for launching the first signal portion into the optical medium.

21. The apparatus of claim 18 wherein a fiber-coupled polarization beam combiner is used to combine one or more back reflections with the second signal portion.

22. A method comprising:
inducing one or more phase variations between orthogonally polarized signal portions in an input frequency-swept sinusoidal optical signal, wherein one or more phase variations result from propagation through one or more internal or external optical mediums; and
transmitting the input frequency-swept sinusoidal optical signal through a Kerr phase interrogator, wherein the Kerr phase interrogator converts the input frequency-swept sinusoidal optical signal with one or more phase variations into an output frequency-swept sinusoidal optical signal with one or more corresponding power variations, thereby performing an all optical beat acquisition.

23. The method of claim 22 , wherein the orthogonally polarized signal portions in the input frequency-swept sinusoidal optical signal have identical frequencies.

24. The method of claim 22 , wherein the orthogonally polarized signal portions in the input frequency-swept sinusoidal optical signal have different frequencies.

25. A method comprising:
inducing one or more phase variations between orthogonally polarized signal portions of an input frequency-swept sinusoidal optical signal, to thereby produce an input frequency-swept sinusoidal optical signal having one or more phase variations, wherein the one or more phase variations result from propagation of the orthogonally polarized signal portions across separate signal paths; and
launching the input frequency-swept sinusoidal optical signal having the one or more phase variations into an input of a Kerr phase-interrogator, to thereby produce an output frequency-swept sinusoidal optical signal having one or more power variations at an output of the Kerr phase interrogator, wherein the one or more power variations at the output of the Kerr phase-interrogator correspond to the one or more phase variations at the input of the Kerr phase-interrogator.

26. The method of claim 25 wherein the orthogonally polarized signal portions of the input frequency-swept sinusoidal optical signal have identical frequencies.

27. The method of claim 25 wherein

Assignees

• Univ Ottawa

Inventors

• Baker Chams
• Bao Xiaoyi

Classifications

• G01M11/3181

  Reflectometers dealing with polarisation · CPC title

• G01M11/3172 Primary

  Reflectometers detecting the back-scattered light in the frequency-domain, e.g. OFDR, FMCW, heterodyne detection · CPC title

• G01L1/242

  the material being an optical fibre · CPC title