Setup Parameters And What They Do - Agilent Technologies 86038A User Manual

Setup Parameters and What They Do

Making Measurements
Setup Parameters and What
They Do
A family of setup parameters allow the user to optimize 86038A
performance for a wide variety of measurement applications. Following is
a brief description of the setup parameters. For a complete description of
each parameter, refer to "Function Reference" on page 87.
Wavelength range
The range of wavelengths over which the measurements are taken,
usually entered by means of start and stop wavelengths.
Wavelength increment
The wavelength separation of adjacent measurement samples. In the
stepped mode, this is the wavelength range divided by the number of steps
minus one. In the swept mode, it is the wavelength range divided by the
number of trace points less one.
Modulation frequency
The frequency of the AM modulation impressed on the optical signal by
the modulator inside the optical test set. The modulation frequency helps
determine wavelength resolution and sensitivity.
Samples/Point
The number of times the recovered RF amplitude and phase are measured
at each measurement wavelength (trace point). In the swept mode only a
single sample is taken. In the stepped mode, the number of samples may
be selected over a wide range. The samples are averaged to reduce the
effect of instrumentation noise.
During polarization dependent measurements (DGD and PDL), the number
of samples are taken while the polarization state is being scanned.
Approximately 201 samples should be taken to ensure that a statistically
sufficient sampling of the polarization states has been obtained. Fewer
samples will provide a faster measurement at the expense of larger
variability (noise). If the operating environment is not controlled for
temperature and vibration, too many samples/point can result in
erroneously high values of DGD and PDL.
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Agilent 86038A Optical Dispersion Analyzer, Third Edition