Tektronix OM4006D, User Manual

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Appendix C: Calibration and adjustment (RT oscilloscope)
Click Run on the oscilloscope to get a rapidly updating display. You should
see 100 to 500 MHz sine waves.
Move the SM fi ber around until you get most signal on RX channels X-I and
X-Q (at least 3:1 ratio between X-I and Y-I. This is most easily done with a
polarization controller).
Tape the fi ber down so that you continue to get most signal on X-I and X-Q.
Click Single on the oscilloscope.
View and correct the
X-polarization calibration
(RT)
1. Use the Optametra OUI to connect to the oscilloscope. Record length of
~20,000 points recommended in single block (BlockSize > 20,000).
2. Display the MATLAB Engine Window, the X-Constellation Window and the
Y-Constellation Window. Close other windows.
3. Put DispCalEllipses in the MATLAB Engine Window of the OUI. Delete
everything else in the MATLAB Engine Window.
4. Click Run on the Optametra OUI.
5. Observe that the ellipses are displayed on the Constellation plots. Right now
only the X-constellation has a signal. The green trace should line up with the
blue circle in the X-constellation plot.
6. If the green trace in X-Constellation is elliptical:
Click Stop .
Enter CorrectX in the separate MATLAB Application Window.
Copy and paste the resulting pHyb statement before DispCalEllipses in the
MATLAB Engine window in the OUI as shown in the following image.
116 OM4000D Series Coherent Lightwave Signal Analyzer