Agilent Technologies 86038B User Manual page 145

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Agilent 86038B Photonic Dispersion and Loss Analyzer, Second Edition
Phase dynamic accuracy (PDA) is used to correct for amplitude-
to-phase conversion effects in the measurement receiver. The
command to enable it:
pdlaClient.NormalizationRange.PDAEnabled = True
7 Measure
Trigger the measurement, then wait for the sweep to complete.
This looks very much like normalization:
' Make sure not connected for normalization
MsgBox ("Connect PDLA for measurement")
' Start the sweep
pdlaClient.Actions.Measure
' Let sweep get started before polling
Sleep 1000
Dim elapsedTime As Double
elapsedTime = 0
' Poll the PDLA waiting for the sweep to complete
' NOTE: 30 minutes may not be long enough!
Do
DoEvents
Sleep (100)
elapsedTime = elapsedTime + 100
If elapsedTime / 1000 / 60 > 30 Then Exit Do
Loop Until pdlaClient.Status.TriggerComplete = True
8 Transfer Data
Now that there is valid data in the PDLA, you will want to
transfer it out. To determine the wavelength axis, read the start
and stop wavelengths and the number of points (You can
determine the number of points in the returned arrays.) then
calculate the wavelength for each point as part of your
application.
When the PDLA takes the derivative of group delay to calculate
chromatic dispersion, the effective wavelength axis shifts one-
half of a point spacing upwards (and there is one less point.) So,
the wavelength queries force you to specify the measurement
type, so you can query the correct wavelengths. Gain, Group
Delay, DGD, and PLDL share the same wavelengths, CD, 2nd
order PMD, PCD and Depol. Rate all use the offset wavelengths.
This example queries the gain:
Dim gainData() As Double
' Get the data and figure out the wavelength axis
gainData = pdlaClient.Results.YData(eMeasurementType_Gain,
eODAPort_One)
npoin = UBound(gainData) - LBound(gainData)+1
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