Integrated polarimeter in an optical line system

• US 10,161,798 B2
• Filed: 06/09/2016
• Issued: 12/25/2018
• Est. Priority Date: 06/09/2016
• Status: Active Grant

• Current Assignee: Ciena Corporation
• Original Assignee: Ciena Corporation
• Inventors: Pei, Yinqing, Archambault, Jean-Luc, Boertjes, David W., Doucet, David R.
• Primary Examiner(s): Cors, Nathan M
• Application Number:
  US15/177,982
• Publication Number:
  US 20170356805A1
• Time in Patent Office: 929 Days
• CPC Class Codes: G01J 4/00 Measuring polarisation of light
• CPC Class Codes: G02B 6/4216 incorporating polarisation-maintaining fibres polarisation-maintaining fibres per se G02B6/105
• CPC Class Codes: H01S 3/0007 Applications not otherwise provided for working metals or other materials by laser beam B23K26/00; using photons to produce a reactive propulsive thrust F03H3/00; optical recording of measured values in general G01D15/14; optics in general G02B; holographic processes or apparatus G03H; optical marking or sensing of data record carriers G06K7/10 - G06K7/14, G06K15/12; injection heating of plasma by laser H05H1/22; acceleration of neutral particles by electromagnetic wave pressure H05H3/04
• CPC Class Codes: H04B 10/0775 Performance monitoring and measurement of transmission parameters
• CPC Class Codes: H04B 2210/078 using a separate wavelength

Abstract

A polarimeter system integrated into an optical line system includes a transmitter coupled to a transmit filter communicatively coupled to an output port in an optical line device, wherein the transmitter is configured to generate a polarization probe signal, and wherein a wavelength of the polarization probe signal is configured to operate in-service with traffic-bearing channels on the output port; and a polarimeter receiver coupled to a receive filter communicatively coupled to an input port in the optical line device, wherein the polarimeter receiver is configured to vary arrangement of input light from the filter and to measure various outputs of the varied arrangement to derive measurement of State of Polarization (SOP) of the input light.

Claims

1. A polarimeter system integrated into an optical line system, the polarimeter system comprising:

a transmitter coupled to a transmit filter communicatively coupled to an output port in an optical line device, wherein the transmitter is configured to generate a polarization probe signal, and wherein a wavelength of the polarization probe signal is configured to operate in-service with traffic-bearing channels on the output port; and

a polarimeter receiver coupled to a receive filter communicatively coupled to an input port in the optical line device, wherein the polarimeter receiver is configured to vary arrangement of input light of a corresponding polarization probe signal from the receive filter and to measure various outputs of the varied arrangement to derive a measurement of State of Polarization (SOP) of the input light,

wherein the polarimeter system is located at a first node in the optical line system, and wherein the polarimeter system further comprises at a second node, opposite the first node and communicatively coupled thereto by two fibers;

an amplifier coupled to a second receive filter in a second optical line device, wherein the amplifier is configured to receive the polarization probe signal from the second receive filter, amplify the polarization probe signal, and loop back the polarization probe signal to the polarimeter receiver via a second transmit filter.

2. The polarimeter system of claim 1, wherein the optical line device comprises one or more of a Raman amplifier module, an Erbium Doped Fiber Amplifier (EDFA) module, an Optical Supervisory Channel (OSC) module, an Optical Time Domain Reflectometer (OTDR) module, a modem, and a pluggable module adapted to plug into any of the foregoing modules.

3. The polarimeter system of claim 1, wherein the polarimeter system operates continuously while the optical line system is in-service to collect SOP data over time to detect SOP transients on a specific span in the optical line system based on the collected SOP data over time.

4. The polarimeter system of claim 1, wherein the polarimeter receiver is implemented with a plurality of passive fiber optic components to provide the varied arrangement and a plurality of detectors to measure the various outputs.

5. The polarimeter system of claim 4, wherein the plurality of passive fiber optic components comprises a Polarization Maintaining (PM) coupler configured to receive the input light, PM fiber coupled to outputs of the PM coupler, a 45°

alignment associated with one output of the PM coupler, and Polarization Beam Splitters (PBSs) coupled to four detectors for providing i₁, i₂, i₃, and i₄.

6. The polarimeter system of claim 4, wherein the plurality of passive fiber optic components comprises a Polarization Maintaining (PM) coupler configured to receive the input light, PM fiber coupled to outputs of the PM coupler, a 45°

alignment associated with one output of the PM coupler, polarizers coupled to two detectors for providing i₁ and i₃, and another detector coupled to an input to provide total input power for estimation of i₂ and i₄ based on the total power and the measurement of i₁ and i₃.

7. The polarimeter system of claim 1, wherein the optical line device comprises the polarimeter system and an Optical Time Domain Reflectometer (OTDR), wherein the transmitter is shared between the polarimeter system and the OTDR based on configuration.

8. The polarimeter system of claim 1, wherein the wavelength of the polarization probe signal is outside of the C-band, greater than 1500 nm to avoid Raman pump lasers, and different from wavelengths for Optical Supervisory Channels (OSCs).

9. A polarimeter system integrated into an optical line system, the polarimeter system comprising:

a transmitter coupled to a transmit filter communicatively coupled to an output port in an optical line device, wherein the transmitter is configured to generate a polarization probe signal, and wherein a wavelength of the polarization probe signal is configured to operate in-service with traffic-bearing channels on the output port; and

a polarimeter receiver coupled to a receive filter communicatively coupled to an input port in the optical line device, wherein the polarimeter receiver is configured to vary arrangement of input light of a corresponding polarization probe signal from the receive filter and to measure various outputs of the varied arrangement to derive a measurement of State of Polarization (SOP) of the input light,

wherein the polarimeter system operates continuously while the optical line system is in-service to collect SOP data over time to detect SOP transients on a specific span in the optical line system based on the collected SOP data over time,

wherein the polarimeter system is located at a first node in the optical line system, and wherein the polarimeter system further comprises at a second node, opposite the first node and communicatively coupled thereto by two fibers;

an amplifier coupled to a second receive filter in a second optical line device, wherein the amplifier is configured to receive the polarization probe signal from the second receive filter, amplify the polarization probe signal, and loop back the polarization probe signal to the polarimeter receiver via a second transmit filter.

10. The polarimeter system of claim 9, wherein the optical line device comprises one or more of a Raman amplifier module, an Erbium Doped Fiber Amplifier (EDFA) module, an Optical Supervisory Channel (OSC) module, an Optical Time Domain Reflectometer (OTDR) module, a modem, and a pluggable module adapted to plug into any of the foregoing modules.

11. The polarimeter system of claim 9, wherein the polarimeter receiver is implemented with a plurality of passive fiber optic components to provide the varied arrangement and a plurality of detectors to measure the various outputs.

12. The polarimeter system of claim 9, wherein the wavelength of the polarization probe signal is outside of the C-band, greater than 1500 nm to avoid Raman pump lasers, and different from wavelengths for Optical Supervisory Channels (OSCs).

13. A polarimeter system integrated into an optical line system, the polarimeter system comprising:

a transmitter coupled to a transmit filter communicatively coupled to an output port in an optical line device, wherein the transmitter is configured to generate a polarization probe signal, and wherein a wavelength of the polarization probe signal is configured to operate in-service with traffic-bearing channels on the output port; and

a polarimeter receiver coupled to a receive filter communicatively coupled to an input port in the optical line device, wherein the polarimeter receiver is configured to vary arrangement of input light of a corresponding polarization probe signal from the receive filter and to measure various outputs of the varied arrangement to derive a measurement of State of Polarization (SOP) of the input light,

wherein the polarimeter receiver is implemented with a plurality of passive fiber optic components to provide the varied arrangement and a plurality of detectors to measure the various outputs, and

wherein the plurality of passive fiber optic components comprises a Polarization Maintaining (PM) coupler configured to receive the input light, PM fiber coupled to outputs of the PM coupler, a 45°

alignment associated with one output of the PM coupler, polarizers coupled to two detectors for providing i₁ and i₃, and another detector coupled to an input to provide total input power for estimation of i₂ and i₄ based on the total power and the measurement of i₁ and i₃.

14. The polarimeter system of claim 13, wherein the polarimeter system is located at a first node in the optical line system, and wherein the polarimeter system further comprises at a second node, opposite the first node and communicatively coupled thereto by two fibers:

an amplifier coupled to a second receive filter in a second optical line device, wherein the amplifier is configured to receive the polarization probe signal from the second receive filter, amplify the polarization probe signal, and loop back the polarization probe signal to the polarimeter receiver via a second transmit filter.

15. The polarimeter system of claim 13, wherein the optical line device comprises one or more of a Raman amplifier module, an Erbium Doped Fiber Amplifier (EDFA) module, an Optical Supervisory Channel (OSC) module, an Optical Time Domain Reflectometer (OTDR) module, a modem, and a pluggable module adapted to plug into any of the foregoing modules.

16. The polarimeter system of claim 13, wherein the optical line device comprises the polarimeter system and an Optical Time Domain Reflectometer (OTDR), wherein the transmitter is shared between the polarimeter system and the OTDR based on configuration.

17. The polarimeter system of claim 13, wherein the wavelength of the polarization probe signal is outside of the C-band, greater than 1500 nm to avoid Raman pump lasers, and different from wavelengths for Optical Supervisory Channels (OSCs).