Optical power measurement in a passive optical network

Patent metadata

Field	Value
Publication number	US-10270554-B2
Application number	US-201715822339-A
Country	US
Kind code	B2
Filing date	Nov 27, 2017
Priority date	Sep 22, 2015
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

A device and method for optical power measurement in an optical network supporting upstream and downstream signal propagation along an optical transmission path. The device includes an upstream wavelength analyzer receiving upstream light extracted from the optical transmission path and configured to determine an upstream spectral characteristic of the extracted upstream light. The device also includes a downstream filter assembly receiving downstream light extracted from the optical transmission path and configured to spectrally split the extracted downstream light into a plurality of downstream signals, one of which corresponding to a downstream signal of interest. The device further includes a processing unit configured to identify, based on the upstream spectral characteristic, the downstream signal of interest among the downstream filtered signals, and a downstream optical power meter assembly coupled to the downstream filter assembly and configured to measure an optical power parameter of the downstream signal of interest.

First claim

The invention claimed is:

1. A device for optical power measurement in an optical network supporting upstream and downstream signal propagation along an optical transmission path, the device comprising:
an upstream wavelength analyzer receiving upstream light extracted from the optical transmission path and configured to determine an upstream spectral characteristic of the extracted upstream light;
a downstream filter assembly receiving downstream light extracted from the optical transmission path and configured to spectrally split the extracted downstream light into a plurality of downstream filtered signals, one of which corresponding to a downstream signal of interest;
a processing unit configured to identify, based on the upstream spectral characteristic, the downstream signal of interest among the plurality of downstream filtered signals; and
a downstream optical power meter assembly coupled to the downstream filter assembly and configured to measure an optical power parameter of the downstream signal of interest.

2. The device of claim 1 , wherein the upstream wavelength analyzer is configured to output the upstream spectral characteristic as a detection signal corresponding to a wavelength value of the extracted upstream light.

3. The device of claim 1 , wherein the upstream wavelength analyzer is configured to output the upstream spectral characteristic as a detection signal conveying information about a presence of the extracted upstream light in a specific upstream spectral range.

4. The device of claim 3 , wherein the specific upstream spectral range corresponds to one among a first upstream spectral band ranging from about 1260 nm to 1280 nm, a second upstream spectral band ranging from about 1290 nm to about 1330 nm, and a third upstream spectral band ranging from about 1524 nm to about 1544 nm.

5. The device of claim 1 , wherein the processing unit is configured to identify the downstream signal of interest among the plurality of downstream filtered signals by determining an expected value of a spectral position of the downstream signal of interest.

6. The device of claim 1 , wherein the processing unit is configured to identify the downstream signal of interest among the plurality of downstream filtered signals by determining an expected downstream spectral range in which to find the downstream signal of interest.

7. The device of claim 6 , wherein the expected downstream spectral range corresponds to one among a first downstream spectral band ranging at least from 1575 nm to about 1580 nm, a second downstream spectral band ranging from about 1480 nm to about 1500 nm, a third downstream spectral band ranging from about 1550 nm to about 1560 nm, and a fourth downstream spectral band ranging from about 1596 nm to about 1603 nm.

8. The device of claim 1 , wherein the optical network supports coexistence of at least a first network standard and a second network standard, the first and second network standards having spectrally distinct first and second upstream transmission bands, and wherein the upstream wavelength analyzer comprises:
an upstream optical power splitter assembly configured to split the extracted upstream light into a first upstream light component and a second upstream light component;
an upstream filter assembly configured to filter, as a filtered upstream signal, the second upstream light component in a passband containing only one of the first and second upstream transmission bands; and
an upstream detection assembly configured to measure a first optical power parameter of the first upstream light component and a second upstream optical power parameter of the filtered upstream signal, the upstream detection assembly generating a detection signal based on the first and second optical power parameters, the detection signal being indicative of the upstream spectral characteristic and conveying information about a presence of the upstream light in one of the first and second upstream transmission bands.

9. The device of claim 8 , wherein the first upstream transmission band ranges from about 1524 nm to about 1544 nm and the second upstream transmission band ranges from about 1290 nm to about 1330 nm.

10. The device of claim 9 , wherein, when the extracted upstream light is found to be present in the first upstream transmission band, the processing unit determines that the downstream signal of interest lies in a first downstream transmission band ranging from about 1596 nm to about 1603 nm, and wherein, when the extracted upstream light is found to be present in the second upstream transmission band, the processing unit determines that the downstream signal of interest lies in a second downstream transmission band ranging from about 1480 nm to about 1500 nm.

11. The device of claim 8 , wherein the first upstream transmission band ranges from about 1260 nm to about 1280 nm and the second upstream transmission band ranges from about 1290 nm to about 1330 nm.

12. The device of claim 11 , wherein, when the extracted upstream light is found to be present in the first upstream transmission band, the processing unit determines that the downstream signal of interest lies in a first downstream transmission band ranging from about 1575 nm to about 1580 nm, and wherein, when the extracted upstream light is found to be present in the second upstream transmission band, the processing unit determines that the downstream signal of interest lies in a second downstream transmission band ranging from about 1480 nm to about 1500 nm.

13. The device of claim 1 , wherein the optical network supports coexistence of at least a first network standard and a second network standard, the first network standard having a first upstream transmission band ranging from about 1524 nm to about 1544 nm and the second network standard having a second upstream transmission band ranging from about 1290 nm to about 1330 nm, wherein, when the extracted upstream light is found to be present in the first upstream transmission band, the processing unit determines that the downstream signal of interest lies in a first downstream transmission band ranging from about 1596 nm to about 1603 nm, and wherein, when the extracted upstream light is found to be present in the second upstream transmission band, the processing unit determines that the downstream signal of interest lies in a second downstream transmission band ranging from about 1480 nm to about 1500 nm.

14. A method for optical power measurement in an optical network supporting upstream and downstream signal propagation along an optical transmission path, the method comprising:
receiving upstream light extracted from the optical transmission path;
determining an upstream spectral characteristic of the extracted upstream light;
receiving downstream light extracted from the optical transmission path;
spectrally splitting the extracted downstream light into a plurality of downstream filtered signals, one of which constituting a downstream signal of interest;
identifying, based on the upstream spectral characteristic, the downstream signal of interest among the plurality of downstream filtered signals; and
measuring an optical power parameter of the downstream signal of interest.

15. The method of claim 14 , wherein determining the upstream spectral characteristic comprises generating a detection signal corresponding to a wavelength value of the extracted upstream light.

16. The method of claim 14 , wherein determining the upstream spectral characteristic comprises generating a detection signal conveying information about a presence of the extracted upstream light i

Assignees

• Exfo Inc

Inventors

• Ruchet Bernard
• L'Heureux Mario
• Gariepy Daniel
• Morin-Drouin Etienne

Classifications

• H04B10/07955 Primary

  Monitoring or measuring power · CPC title

• H04J14/0221 Primary

  Power control, e.g. to keep the total optical power constant · CPC title

• H04J14/02 Primary

  Wavelength-division multiplex systems · CPC title