This part of IEC 61290 applies to all commercially available optical amplifiers (OAs) including
optical fibre amplifiers (OFAs) using active fibres and semiconductor optical amplifiers (SOAs)
using semiconductor gain media.
Polarization-mode dispersion (PMD) causes an optical pulse to spread in the time domain.
This dispersion could impair the performance of a telecommunications system. The effect can
be related to differential group velocity and corresponding arrival times of different
polarization components of the signal. For a narrow-band source, the effect can be related to
a differential group delay (DGD) between pairs of orthogonally polarized principal states of
polarization (PSP).
This test method describes a procedure for measuring the PMD of OAs. The measurement
result is obtained from the measurement of the normalised Stokes parameters at two closely
spaced wavelengths. The mathematical basis together with an example of calculation for the
Poincaré sphere analysis (PSA) method to calculate PMD is provided in the technical report
IEC 61292-5.
The method described herein has been shown to be immune to polarization-dependent gain
(PDG) and polarization-dependent loss (PDL) up to approximately 1 dB [*].
Although the PSA, in practic e, is applicable to unpumped (that is, unpowered) OAs, the PSA
technique in this standard applies to pumped (that is, powered) OAs only.