Method of measuring optical return loss

Patent metadata

Field	Value
Publication number	US-2016197672-A1
Application number	US-201414443806-A
Country	US
Kind code	A1
Filing date	Jul 22, 2014
Priority date	Jul 22, 2013
Publication date	Jul 7, 2016
Grant date	—

Abstract

A method of calculating optical return loss (ORL) in a fiber network includes injecting a plurality of pulses of light at a known first power level into the fiber network, determining a location at which end reflection is detected, measuring a second power level of each of a plurality of returned pulses of light, measuring a third power level of a pulse of light returned from the determined location, and calculating ORL based on the first power level, the second power level and the third power level.

First claim

1 . A method of calculating optical return loss (ORL) in a fiber network, the method comprising:
injecting a plurality of pulses of light at a known first power level into the fiber network; determining a location at which end reflection is detected; measuring a second power level of each of a plurality of returned pulses of light; measuring a third power level of a pulse of light returned from the determined location; and calculating ORL based on the first power level, the second power level and the third power level.

2 . The method according to claim 1 , wherein
the calculating further comprises excluding the third power level from the calculation.

3 . The method according to claim 1 , wherein
the calculating further comprises calculating the ORL using the formula: ORL=10×log Σ(P inject i /P return i ), where P denoted power level and i denotes samples taken over a period of time until the injected plurality of pulses have exited fiber and all reflections have been received.

4 . The method according to claim 3 , wherein
the calculating further comprises excluding the third power level from the calculation.

5 . The method according to claim 1 , wherein
the first power level, the second power level and the third power level are measured in watts.

6 . The method according to claim 1 , wherein
the measuring the second power level further comprises measuring the second power level of each of the plurality of returned pulses of light per unit time.

7 . A non-transitory computer readable recording medium storing a program used in an apparatus, including at least one processor, for calculating optical return loss (ORL) in a fiber network, the program causing said at least one processor to:
inject a plurality of pulses of light at a known first power level into the fiber network; determine a location at which end reflection is detected; measure a second power level of each of a plurality of returned pulses of light; measure a third power level of a pulse of light returned from the determined location; and calculate ORL based on the first power level, the second power level and the third power level.

8 . The non-transitory computer readable recording medium of claim 7 , the program further causes said at least one processor to:
exclude the third power level from the calculation.

9 . The non-transitory computer readable recording medium of claim 7 , the program further causes said at least one processor to:
calculate the ORL using the formula: ORL=10×log Σ(P inject i /P return i ), where P denoted power level and i denotes samples taken over a period of time until the injected plurality of pulses have exited fiber and all reflections have been received.

10 . The non-transitory computer readable recording medium of claim 9 , the program further causes said at least one processor to:
exclude the third power level from the calculation.

11 . The non-transitory computer readable recording medium of claim 7 , wherein
the first power level, the second power level and the third power level are measured in watts.

12 . The non-transitory computer readable recording medium of claim 7 , the program further causes said at least one processor to:
measure the second power level of each of the plurality of returned pulses of light per unit time.

Assignees

• Afl Telecommunications Llc

Inventors

• Scholten Michael

Classifications

• H04B10/071

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

• H04B10/07955 Primary

  Monitoring or measuring power · CPC title

• G01M11/3109 Primary

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