HP 86037B, Instruction Manual

Page: 59 / 204

3-3
Normalization
Normalization
Because normalization data is saved in a file, it can be recalled and used at a
later time. It is sometimes possible to use normalization files four or five days
old and still obtain good measurement results. When in doubt, click the Nor-
malization Verification button to quickly check the quality of the normaliza-
tion.
Test setup normalization
The following are two examples of devices for which you can create normaliza-
tion data:
• A fiber jumper connected between the test ports of the CD system. Follow-
ing the normalization an end of the jumper will be disconnected and the de-
vice under test inserted.
• A pair of fiber jumpers (connected by a through adapter) connected be-
tween the test ports of the CD system. Following the normalization, the
through adapter is removed and the test device inserted.
Modulator bias adjustment
Perform the modulator bias adjustment at the beginning of a measurement
session. The modulator is automatically biased to the optimum (quadrature)
performance condition. This procedure does not need to be performed before
each individual measurement, and can be set to occur automatically when a
normalization is performed.
Laser normalization
This procedure normalizes the system between 1515 nm and 1580 nm, in 1 nm
steps. Correction constants are determined for the laser and stored. Perform
this procedure when the system is installed; it does not need to be performed
before each individual measurement.