Atec Anritsu_MS9720A - Manual (Page 8)

8
Long-Term Measurement
The MS9720A has a long-term measurement function for
displaying the wavelength, level and SNR, etc., as a table,
and saving the average, maximum and minimum value of
each measurement to floppy disk as a text file at a set mea-
surement interval. During long-term measurement, wave-
length calibration is performed every 6 hours, and level cali-
bration every 1 hour.
PMD Measurement
It is also possible to measure the PMD (Polarization Mode
Dispersion), an important factor determining the upper limit
of the transmission bit rate in optical fiber amplifier systems.
The MS9720A has a function for calculating PMD using a
fixed analyzed method which is one measurement method.
The PMD can be measured easily by using the following
type of measurement system.
The diagram below shows PMD measurement of a 1 m
PANDA fiber.
NF Measurement
The MS9720A can measure NF using interpolation technic
(level fitting method). In the MS9720A NF measurement
function, the ASE (Amplified Spontaneous Emission) is cal-
culated by the averaging the sum of the level at two points
separated by a fixed wavelength from the signal wavelength
of the EDFA output. The following screens show a mea-
surement of the NF of an EDFA amplifying a WDM signal.
SLD output
Optical input
MS9720A
PRM
PRM
PRM:Polarization rotation module (sold separately)