Re: [10GMMF] Task 2 and 4 slides for Dec15th - OM3 fibre measurements
Joerg,
I agree that it is possible to find
fibers that cause problems with any given launch. But we should review
the present evidence. Throughout the several new launch condition examinations
of the .aq task force, the nominal 20 um offset launch condition continues
to be one of the optimal launches for OM1 fiber. What has not yet
been well examined by .aq is the launch condition for OM2 fibers. It
may turn out that once we model OM2, the present offset launch patch cord
spec for 50 um fibers (nominal 13 um offset) can be better optimized for
EDC receivers. Until we complete that part of the modeling, it is
premature to assume that the present OM2 launch condition is the best one
to choose, and even further astray to apply its present inner EF limit
to OM1 when it has already been shown to be sub-optimal by about 0.7 dB.
Regards,
Paul Kolesar
SYSTIMAX® SOLUTIONS
1300 East Lookout Drive
Richardson, TX 75082
Phone: 972.792.3155
Fax: 972.792.3111
eMail: pkolesar@systimax.com
"Joerg-R. Kropp"
<Joerg.Kropp@INFINEON.COM>
Sent by: owner-stds-802-3-10gmmf@ieee.org
12/20/2004 05:07 AM
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| Re: [10GMMF] Task 2 and 4 slides for
Dec15th - OM3 fibre measurements |
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Paul,
thanks for having a close look
to the launch conditions and the discussion of the presented results.
In the last months task groups
discussed several results on different fibers with the various deviations
from the ideal profile. If you are looking for bad behaving fibers you
will find samples with deviations on all radial sections of the core. Our
"kink fiber" (I gave some presentations on it) behaves badly
just within the range of the current offset patchcord but is very good
for all other launches. Our "benchmark fiber" behaves badly for
nearly all radial launches instead of pure central launch. Agilent presented
results of a fiber which behaves badly in the center launch situation but
is well suited for offset launch. Beside this examples there are hundrets
of fibers which will behave well, but we focused (offcause) in the last
months on the critical examples in order to understand better all the fiber
issues.
The allover result of all the
examinations for me is that most of the (old) fibers (OM1 and OM2 ) will
work better with offset launch than with central launch because of the
central dip deviations (and because of the OFL selection criterion which
weights strongest the larger radius areas). For these fibers we need to
avoid the launch in the central region. Since the central defects are similar
for OM1 and OM2 fibers we should use the same spec for both and we should
keep it at 6µm for EFL <30%. The spec for the large radii must be adjusted
to the different fiber diameters of OM1 and OM2.
The center launch spec for the
OM3 fibers seems to me to be very usefull for the OM1/OM2 fibers with deviations
at larger radii because many of them will behave very good with center
launch (because the OFL bandwidth has to exceed the bandwidth spec and
if there is a outer defect there has to be a very good center area).
Regards
Joerg
Infineon Technologies Fiber Optics GmbH
MOD CE
Dr. Joerg-R. Kropp
Senior Staff Expert
Wernerwerkdamm 16
D-13629 Berlin / Germany
Phone -49-30-85400-4918
Fax -49-30-85400-4900
Mail joerg.kropp@infineon.com
-----Original Message-----
From: owner-stds-802-3-10gmmf@ieee.org [mailto:owner-stds-802-3-10gmmf@ieee.org]
On Behalf Of Paul Kolesar
Sent: Freitag, 17. Dezember 2004 17:43
To: STDS-802-3-10GMMF@listserv.ieee.org
Subject: Re: [10GMMF] Task 2 and 4 slides for Dec15th - OM3 fibre measurements
Joerg,
thanks for the confirmation and clarification.
Regarding the EF at 30%, if the radial limit is a small as 6 um, then singlemode
launches offset by as little as 8 um would be allowed. Launches in
this range have been shown by John Ewen this week to produce the largest
PIE-D in OM1 fibers, with values about 0.7 dB higher than those for 20
um offset launches. So a spec this loose seems considerably sub-optimal.
Regards,
Paul Kolesar
SYSTIMAX® SOLUTIONS
1300 East Lookout Drive
Richardson, TX 75082
Phone: 972.792.3155
Fax: 972.792.3111
eMail: pkolesar@systimax.com
"Joerg-R. Kropp"
<Joerg.Kropp@INFINEON.COM>
Sent by: owner-stds-802-3-10gmmf@ieee.org
12/17/2004 05:11 AM
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| Re: [10GMMF] Task 2 and 4 slides for
Dec15th - OM3 fibre measurements |
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Paul,
you are correct! The Bandwidth diagram is scaled for a length of 300m of
a 1300nm transmission. It is just the bandwidth which results from the
pulse forms over the 300m length (large diagram on each slide). In addition
to that bandwidth dependence on the offset radius of the launch I included
the calculated OFL bandwidth of the fiber by a straight line in order to
give some additional information.
A statement to the EFD values:
I agree that the lower borders for OM1 and OM2 offset launch should be
adjusted to the same value in order to get no difference between both,
my favorite for that is < 30% for EFD at 6µm.
The reason of the definition of the center border is to avoid to large
power in the central region because of the possible dip in the center of
the fiber. Since this dip is in general of the same size for OM1 and OM2
fibers it makes no sense to define different values for the EFD borders
in that area.
Joerg
-----Original Message-----
From: owner-stds-802-3-10gmmf@ieee.org [mailto:owner-stds-802-3-10gmmf@ieee.org]
On Behalf Of Paul Kolesar
Sent: Freitag, 17. Dezember 2004 01:35
To: STDS-802-3-10GMMF@listserv.ieee.org
Subject: Re: [10GMMF] Task 2 and 4 slides for Dec15th - OM3 fibre measurements
Joerg,
I believe I've answered my first question. The OFL line is the raw
OFL BW at 1300 nm not normalized to GHz-km, simply GHz. The value
is 0.5GHz-km/0.3km = 1.67GHz. Correct?
Paul
Paul Kolesar <PKOLESAR@SYSTIMAX.COM>
Sent by: owner-stds-802-3-10gmmf@ieee.org
12/16/2004 05:38 PM
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| Re: [10GMMF] Task 2 and 4 slides for
Dec15th - OM3 fibre measurements |
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Joerg,
In your and Stefano's contribution to Task2/4 this week you provide
bandwidth plots on the right side of three slides showing the trend with
offset. I have two questions:
1. In each of these there is a horizontal line at about 1.6 GHz-km that
appears to be labeled OFL. Is this the OFL BW at 850 nm?
2. The horizontal axis is labeled "radius of launch (um)". This
can be interpeted in two ways. Is it the encircled flux radius at
perhaps 86% level, or (more likely) the offset radius of the launch?
Thanks in advance for the clarifications.
Paul Kolesar
"Joerg-R. Kropp"
<Joerg.Kropp@INFINEON.COM>
Sent by: owner-stds-802-3-10gmmf@IEEE.ORG
12/15/2004 09:21 AM
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| Re: [10GMMF] Task 2 and 4 slides for
Dec15th - OM3 fibre measurements |
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Jonathan and all,
please find enclosed further simulations about the OM3 transmission and
our proposal based on that simulations.
I hope it will be possible to discuss that today.
I have to cut the presentation into two because of the 100k limit.
Joerg-R. Kropp
Infineon Technologies Fiber Optics
GmbH
MOD CE
Dr. Joerg-R. Kropp
Senior Staff Expert
Wernerwerkdamm 16
D-13629 Berlin / Germany
Phone -49-30-85400-4918
Fax -49-30-85400-4900
Mail joerg.kropp@infineon.com
[attachment "OM3 Fiber EFD PIED1.pdf" deleted by Paul F Kolesar/CommScope]