Optical carrier selector system and method

Patent metadata

Field	Value
Publication number	US-9948389-B2
Application number	US-201415116014-A
Country	US
Kind code	B2
Filing date	Feb 14, 2014
Priority date	Feb 14, 2014
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

An optical carrier selector system is provided for selecting a wanted carrier signal from a multi-carrier signal comprising a plurality of carrier signals. The optical carrier selector system comprises a series of optical filter devices. Each optical filter device of the series comprises an input port for receiving a signal comprising two or more carrier signals, each optical filter device being configured to filter out an unwanted carrier signal. Each optical filter device also comprises an output port for outputting at least the wanted carrier signal and any remaining signals that have not been filtered out by that particular optical filter device, and a drop port for outputting the unwanted carrier signal that is being filtered out by the respective optical filter device. By outputting from a drop port the unwanted carrier signal that is being filtered out by the respective optical filter device, this has the advantage of enabling the operation of the optical carrier selector system to be monitored for proper operation, and controlled or adjusted if necessary.

First claim

The invention claimed is:

1. An optical carrier selector system for selecting a wanted carrier signal from a multi-carrier signal comprising a plurality of carrier signals, the optical carrier selector system comprising:
a series of optical filter devices, wherein each optical filter device of the series comprises:
an input port for receiving a signal comprising two or more carrier signals, each optical filter device being configured to filter out an unwanted carrier signal;
an output port for outputting at least the wanted carrier signal and any remaining signals that have not been filtered out by that particular optical filter device;
a drop port for outputting the unwanted carrier signal that is being filtered out by the respective optical filter device; and
one or more monitoring devices coupled to one or more respective drop ports, for monitoring the optical power of the unwanted carrier signal being filtered out by a respective optical filter device.

2. An optical carrier selector system as claimed in claim 1 , wherein each monitoring device is used to monitor whether the correct unwanted carrier signal has been filtered out by a respective optical filter device, and/or to control fine tuning of one or more filter characteristics of the respective optical filter device.

3. An optical carrier selector system as claimed in claim 1 , further comprising a monitoring device coupled to the output port of the optical filter device in the final stage of the series of optical filter devices, for monitoring the optical power of the wanted carrier signal.

4. An optical carrier selector system as claimed in claim 1 , wherein the optical filter devices are arranged in the series such that adjacent optical filter devices remove carrier signals having non-adjacent frequencies.

5. An optical carrier selector system as claimed in claim 4 , wherein the first and second optical filter devices of the series remove first and second unwanted carrier signals having frequencies which are adjacent to the frequency of the wanted carrier signal.

6. An optical carrier selector system in claim 1 , wherein the system is configured to provide each carrier signal of the multi-carrier signal with a different optical power level.

7. An optical carrier selector system as claimed in claim 1 , further comprising an optical shaping filter adapted to generate imbalance in carrier signals of the multi-carrier signal, prior to the multi-carrier signal being received by the series of optical filter devices.

8. An optical carrier selector system as claimed in claim 1 , further comprising one or more further series of optical filter devices, each of the one or more further series of optical filter devices being configured to select a respective wanted carrier signal from the multi-carrier signal.

9. An optical carrier selector system as claimed in claim 1 , further comprising a controller for controlling the operation of one or more series of optical filter devices, wherein the controller is configured to selectively control which carrier signal frequency is to be filtered out at each optical filter device in a series.

10. An optical carrier selector system as claimed in claim 1 , wherein each optical filter device comprises a micro ring resonator, MRR, and wherein a controller is configured to control the operation of a MRR by controlling the drive current of a heating element associated with the MRR.

11. An optical carrier selector system as claimed in claim 10 , wherein the controller is configured to control the operation of each MRR in a series based on a set of current values I Rx,h,k stored in a first look-up table, each current value representing a current for driving a heating element of a respective MRR, where “Rx” represents a particular series of MRRs, where “h” represents the number of the MRR in a path towards the output of the series, and “k” represents a frequency of a carrier signal which is to be filtered out by a MRR.

12. An optical carrier selector system as claimed in claim 1 , wherein a controller is configured to:
monitor the optical power level received from a drop port of an optical filter device;
check for proper operation of the optical filter device by comparing a monitored current value I IIc with a set of predetermined current values stored in a second look-up table, where “X” represents a particular series of MRRs, where “I” represents the number of the MRR in a path towards the output of the series, and “k” represents a frequency of a carrier signal which is to be filtered out by a MRR.

13. An optical carrier selector system as claimed in claim 1 , wherein a controller is further configured to:
monitor the optical power level of the wanted carrier signal being output from the final optical filter device of a series: and
check for proper operation of the series of optical filter devices by comparing the optical power level of the wanted carrier signal with a predetermined optical power level.

14. An optical carrier selector system as claimed in claim 1 , wherein a controller is configured to fine tune the operation of an optical filter device, wherein the controller is configured to receive an indication over time of the power level at the drop port, and if the power level is determined to vary over time, the controller is configured to tune the optical filter device to correct the variation.

15. A method of controlling the operation of one or more stages of an optical carrier selector system, wherein each stage of an optical carrier selector system comprises a series of optical filter devices for selecting a wanted carrier signal from a multi-carrier signal comprising multiple carrier signals, the method comprising, at each optical filter device, performing the steps of:
receiving at an input port a signal comprising two or more carrier signals;
filtering out an unwanted carrier signal;
outputting from an output port at least the wanted carrier signal and any remaining signals that have not been filtered out;
outputting from a drop port the unwanted carrier signal that was filtered out by the filtering step; and
monitoring the optical power of the unwanted carrier signal being filtered out by a respective optical filter device.

16. A method as claimed in claim 15 , further comprising the steps of using the monitored optical power to determine whether the correct unwanted carrier signal has been filtered out by a respective optical filter device, and/or controlling the fine tuning of one or more filter characteristics of the respective optical filter device.

17. An optical carrier selector arrangement comprising a plurality of optical carrier selector systems, each optical carrier selector systems configured to select a wanted carrier signal from a multi-carrier signal comprising a plurality of carrier signals, the optical carrier selector system comprising:
a series of optical filter devices, wherein each optical filter device of the series comprises:
an input port for receiving a signal comprising two or more carrier signals, each optical filter device being configured to filter out an unwanted carrier signal;
an output port for outputting at least the wanted carrier signal and any remaining signals that have not been filtered out by that particular optical filter device;
a drop port for outputting the unwanted carrier signal that is being filtered out by the respective optical filter device; and
one or more monitoring devices coupled to one or more respective drop ports, for monitoring the optical power of the unwanted carrier signal being filtered out by a respective

Assignees

• Ericsson Telefon Ab L M

Inventors

• D'Errico Antonio
• Castoldi Piero
• Porzi Claudio
• Sambo Nicola

Classifications

• H04J14/0298

  with sub-carrier multiplexing [SCM] · CPC title

• H04J14/0256 Primary

  at the optical channel layer · CPC title

• H04B10/07955 Primary

  Monitoring or measuring power · CPC title

• H04J14/0212

  using optical switches or wavelength selective switches [WSS] · CPC title

• H04J14/0221

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