Impairments in Polarization-Multiplexed DWDM Channels due to Cross- Polarization Modulation Marcus Winter Christian-Alexander Bunge Klaus Petermann Hochfrequenztechnik-Photonik.

Präsentation zum Thema: "Impairments in Polarization-Multiplexed DWDM Channels due to Cross- Polarization Modulation Marcus Winter Christian-Alexander Bunge Klaus Petermann Hochfrequenztechnik-Photonik."—  Präsentation transkript:

1 Impairments in Polarization-Multiplexed DWDM Channels due to Cross- Polarization Modulation Marcus Winter Christian-Alexander Bunge Klaus Petermann Hochfrequenztechnik-Photonik TECHNISCHE UNIVERSITÄT BERLIN Dario Setti http://www.marcuswinter.de/publications/leos2008

2 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik cross-polarization modulation (XPolM)

3 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik XPolM is a nonlinear interchannel effect which randomly rotates the polarization states in time similar to how XPM affects the phase

4 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik nonlinear polarization effects

5 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik distribution of SOPs of a CW probe channel propagation of 10 spans with 10 × 10 Gbps NRZ interfering channels

6 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik distribution of SOPs of a CW probe channel propagation of 10 spans with 10 × 10 Gbps NRZ interfering channels DOP = 0.894

7 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik θ is the deflection from the mean direction φ is the azimuth average SOP

8 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik impairments in PolDM systems

9 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik PolDM subchannel is originally (on average) x-polarized symbol SOP is rotated through XPolM by an angle θ (in Stokes space) from the mean fading crosstalk Jones space visualization

10 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik crosstalk fading

11 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik crosstalk from a single CW channel into orthogonal (y-)polarization DOP = 0.894 crosstalk phase depends on azimuth φ in Stokes space

12 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik fading within a single CW channel (x-polarization) DOP = 0.894 fading

13 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik crosstalk variance vs. CW DOP reduction valid only for the polarization / PMD ensemble only the ensemble statistics of the SOPs are known

14 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik system simulations

15 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik PolDMed (low-power) CW probe and QPSK signal + 10 × 10 Gbps NRZ interferers PolDM DEMUX is aligned to mean CW probe SOP determination of I and Q ROSNR as if it were an (all-zero) 10 Gbaud DQPSK signal

16 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik CW subchannel only – variations are caused by XPM no dependence on DOP 500 iterations with random polarization parameters / NRZ bit patterns

17 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik large ROSNR variation due to non-Gaussian crosstalk within individual members of the ensemble significant dependence on DOP CW probe w/ QPSK PolDM neighbor 500 iterations with random polarization parameters / NRZ bit patterns analytical estimate using Gaussian crosstalk distribution and variance

18 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik summary and conclusions

19 TECHNISCHE UNIVERSITÄT BERLIN Fachgebiet Hochfrequenztechnik XPolM-induced depolarization leads to crosstalk between and fading within PolDM subchannels crosstalk added at the PolDM demultiplexer is Gaussian distributed and predictable (in the statistical average) individual realizations within the statistical ensemble can be significantly non-Gaussian large variation of observed system penalties outage statistics required for a more accurate description