Anritsu MS9740B - Measuring PMD (Polarization Mode Dispersion)

5.4 Measuring PMD (Polarization Mode Dispersion)
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5
Measurement Functions
5.4 Measuring PMD (Polarization Mode Dispersion)
Polarization Mode Dispersion is a phenomenon that widens the width of
optical pulses due to differences in transmission speed between two
polarization modes when an optical pulse is passed through optical fiber
and optical equipment.
Figure 5.4-1 Outline of PMD
The PMD measurement function measures the Diff Group Delay
(differential group delay).
Note:
Accurate measurement is not possible for fiber installations in
unstable environments, such as in air.
The Diff Group Delay cannot be measured, if the multiplex peak
wavelengths do not exist in the spectrum as shown in Figure 5.4-2.
Polarization
axis 1
Polarization
axis 2
Difference
between
polarization
components
Input
optical
pulse
Optical input
polarization axis
1
component
Optical input
polarization axis
2 components
Optical
pulse after
passage
thru
fiber/part
Optical fiber/part