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N7788B "PMD/PDL/Loss" Application (DGD/SOPMD measuring)

Question asked by on Jan 18, 2012
Latest reply on Jan 20, 2012 by
Hello board,
I am actually working with the optical component analyzer N7788B and need some help for the measuring method. I mean the Application "PMD/PDL/Loss" from the Polarisation Navigator Software.
What I want to do:
We have a PMD emulator from fiberpro (PE4200) in our lab and we are not shure how exact/valid are the emulated values (DGD and SoPMD). Therefore I want to meassure that device with the N7788B and a tunable Laser Source (Agilent 81600B). However, the setup is well described in the manual (N7788B) and my measurings are working verry well. BUT...

My Problems:
I am able to set specific values on my DUT (PE4200) such as DGD:100ps / SoPMD:1000s^2.To measure these values I'm using the Application "PMD/PDL/Loss" from the Polarisation Navigator Software. The measuremt results are extremely depended from the Sweep Rate and that does not mean that the highest/lowest rate produce the best result. I did measurings for more sweep rates and somehow the "best"  (nearest to the set value) results at a sweep rate between min and max rate. This is also different for varied DUT set values.
In the beginning I did all the measuring with the highest post processing resolution. Unfortunately I saw that the post processing resolution has also a big influence to the measured value. Here also the highest resolution does not end in the best result value. Resolution values between highest and lower are more effective.

Does someone here know the reason of these impacts?
Does someone know what the best practice is?
Does someone here know a better description as this one from the Agilent N7788B Manual?
Does someone here know some white papers for this kind of DGD, SecondOrderPMD measuring?

I’m sincerely thankful for every help on this side.

Edited by: mkelly on Mar 15, 2012 4:26 AM