PMD Measurement Methods  Fixed Analyzer Method IEC / ITU-T G.650.2/ EIA/TIA Standard FOTP-113  Jones Eigenanalysis Matrix Method IEC / ITU-T G.650.2/ TIA/EIA Standard FOTP-122A Traditional Interferometric Method IEC / ITU-T G.650.2/ TIA/EIA Standard FOTP-124A  General Interferometric Method IEC / ITU-T G.650.2/ TIA/EIA Standard FOTP-124A  Poincare Sphere Method (not presented) ‏ Laboratory use only  State of Polarization method (Not presented) ‏ Laboratory use only  Simple calculation Addition of the root square of the PMD of each section  P-OTDR method Not approved

Fixed-Analyzer Method OSA Analyzer FUT Broadband Source Polarizer Broadband Source OBS 15 MTS 8000 A polarized light is sent over the Fiber Under Test and the transmitted spectrum is analyzed through a polarizer

Fixed-Analyzer Method The RMS width of the Gaussian distribution is calculated. The displayed value is the average DGD. Random mode coupling Delay (ps)‏ Fast Fourier Transform It’s possible to shift to the time domain the analysis of the fixed-analyser response by taking the Fourier Transform of the power fluctuations with wavelength.

Fixed Analyzer Method PMD test set-up PMD Delay (1 st & 2 nd order)‏ PMD Coefficient (1 st & 2 nd order)‏ Statistical Analysis

Fixed-Analyzer Method Advantages  Established in the market  Easy to use: no specific parameter settings necessary  Very fast measurement & good absolute uncertainty  Min DGD and dynamic range suitable for most of network types  Possible to measure through multiple EDFA  Robust and field dedicated method: no moving parts (Fabry- Perot filter technology) limiting risk of failure Drawbacks  Limited to relatively small PMD (<60ps).  Sensitive to input polarization  Averaging necessary but only over 30dB total loss  2 nd order PMD not measured directly but calculated

Jones Matrix Eigenanalysis Method Tunable Narrowband Source Polarizer 3 states A B C FUT Polarimeter A B C J 1 J 2 J 3 J 4 DGD ( 1+ 2) / 2 DGD ( 2+ 3) / 2 DGD ( 3+ 4) / 2 Wavelength (nm)‏ DGD(ps)‏ ( 1+ 2) / 2 The signal of a series of wavelength is split into polarization components and analyzed by the polarimeter thanks to the Jones Matrix. The DGD is obtained from the matrix values at pairs of adjacent wavelengths. The PMD is then given by averaging the obtained DGD values.

Jones Matrix Eigenanalysis Method Advantages  High repeatability and good absolute uncertainty  1 st and 2 nd order PMD measured directly  Not sensitive to input polarization and mode coupling  Wide dynamic range: up to 50dB (using a benchtop light source)  Possible to measure through multiple EDFA  Averaging not necessary but one acquisition required for each wavelength Drawbacks  High cost method for a field solution  Laboratory solution, not field proven nor convenient  Long measurement time  Source non integrated (>5 kg) - Tunable Light Source required, no Hand Held type available

Interferometric method (TINTY) ‏ Broadband Source Polarizer FUT Interferometer Mirror Analyzer Detector Random mode coupling Delay (ps)‏ Autocorrelation peak The result is an interferogram with random phases, and the mean DGD value is determined from the standard deviation of its curve after the autocorrelation peak removal. A polarized broadband signal is sent over the Fiber Under Test and passes an interferometer before it hits the detector.

Interferometric method (TINTY) ‏ Advantages  Established in the market  Good absolute uncertainty but systematic error due to central peak removal  Wide dynamic range: up to 65 dB (using a benchtop light source) ‏ Drawbacks  Not possible to measure through EDFA  Sensitive to input polarization  Limited ease of use: the correct DGD range must be set before testing  Not field solution: risk of failure due to moving parts  Long measurement time - averaging necessary  2 nd order PMD not measured directly

Interferometric method (GINTY) ‏ Polarization Beam Splitter It allows simultaneous detection. The interferogram is obtained without autocorrelation peak. It allows the selection of any input and output states of polarization of the FUT. Polarization Scramblers Broadband Source Polarizer FUT Polarization Scramblers Polarization Beam Splitter Interferometer Mirror Analyzer Detector Detectors

Interferometric method (GINTY) ‏ Advantages  Good absolute uncertainty  Wide dynamic range: up to 47 dB (using a benchtop light source)  Possible to measure through multiple EDFA  Not sensitive to input polarization when using polarization scramblers  Fast measurement (>5s) ‏ Drawbacks  Not established in the market (new method) ‏  Not field solution: Risk of failure due to moving parts  Limited dynamic range with portable light source  Polarization scramblers required  2 nd order PMD not measured directly but calculated  Sensitive to input polarization when no polarization scramblers in place