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Re: [10GMMF] Measured 62MMF connector loss with various offsets

thanks for the experimental validation.  One explanation for the differences between David's calculations and your measurements might be the tolerance on the offset launch position within the offset launch patch cord.  The spec is 20 +/- 3 um for a 62 um fiber.  I believe cords at the high end of this range (i.e. 23 um offset) would tend produce a launch that causes higher loss than cords at the lower end (i.e. 17 um offset).

did you model a nominal (i.e. 20 um) offset?

Paul Kolesar
1300 East Lookout Drive
Richardson, TX 75082
Phone:  972.792.3155
Fax:      972.792.3111

"Joerg-R. Kropp" <Joerg.Kropp@INFINEON.COM>
Sent by: owner-stds-802-3-10gmmf@LISTSERV.IEEE.ORG

08/20/2004 10:47 AM
Please respond to "IEEE 802.3aq 10GBASE-LRM"

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        cc:        (bcc: Paul F Kolesar/CommScope)
        Subject:        [10GMMF] Measured 62MMF connector loss with various offsets

Dear All,

Enclosed you will find the experimental verification of the calculated connector loss for various fiber offsets.
I used standard offset patchcord for 62,5Ám fibers for fiber launch and measured the loss for several offsets of the multimode fiber.
The calculation of David Cunningham for this case fits well to the measured values.


-----Original Message-----
From: [] On Behalf Of David Cunningham
Sent: Mittwoch, 18. August 2004 21:25
Subject: [10GMMF] 62MMF connector loss and draft test link config

Dear All,

As promised on todays Fiber Channel Ad Hoc I attach a PDF file containing the following information:

* My calculated graphs of connector loss versus offset for overfilled launch, steady state launch and 23 um offset single mode launch.

* The agreed draft of the worst-case test configuration for channel time variation measurements with comments from our call to document our reasoning behind the chosen configuration.